Physics World

Pioneers of 2D metals win the Physics World 2025 Breakthrough of the Year

Hamish Johnston — Thu, 18 Dec 2025 14:15:42 +0000

Under pressure A researcher in Beijing operates an apparatus used to make 2D metals. (Courtesy: CAS IOP/Handout via Xinhua)

The Physics World 2025 Breakthrough of the Year is awarded to Guangyu Zhang, Luojun Du and colleagues at the Institute of Physics of the Chinese Academy of Sciences for producing the first 2D sheets of metal. The team produced five atomically thin 2D metals – bismuth, tin, lead, indium and gallium – with the thinnest being around 6.3 Å. The researchers say their work is just the “tip of the iceberg” and now aim to use their new materials to probe the fundamentals of physics. Their breakthrough could also lead to the development of new technologies.

Since the discovery of graphene – a sheet of carbon just one atom thick – in 2004, hundreds of other 2D materials have been fabricated and studied. In most of these, layers of covalently bonded atoms are separated by gaps where neighbouring layers are held together only by weak van der Waals (vdW) interactions, making it relatively easy to “shave off” single layers to make 2D sheets. Many thought that making atomically thin metals would be impossible given that each atom in a metal is strongly bonded to surrounding atoms in all directions.

The technique developed by Zhang, Du and colleagues involves heating powders of pure metals between two monolayer-MoS2/sapphire vdW anvils. Once the metal powders are melted into a droplet, the researchers applied a pressure of 200 MPa and continued this “vdW squeezing” until the opposite sides of the anvils cooled to room temperature and 2D sheets of metal were formed.

“Right now, we have reported five single element metals, but actually we can do more because of the 88 metals in the periodic table,” Zhang explains in today’s episode of the Physics World Weekly podcast. In the podcast, he also talks about the team’s motivation creating 2D metals and some of the possible technological applications of the materials.

The Breakthrough of the Year was chosen by the Physics World editorial team. We looked back at all the scientific discoveries we have reported on since 1 January and picked the most important. In addition to being reported in Physics World in 2025, the breakthrough must meet the following criteria:

Significant advance in knowledge or understanding

Importance of work for scientific progress and/or development of real-world applications

Of general interest to Physics World readers

Before we picked our winners, we released the Physics World Top 10 Breakthroughs for 2025, which served as our shortlist. The other nine breakthroughs are listed below in no particular order.

Finding the stuff of life on an asteroid

Analysing returned samples Tim McCoy (right), curator of meteorites at the Smithsonian’s National Museum of Natural History, and research geologist Cari Corrigan examine scanning electron microscope (SEM) images of a Bennu sample. (Courtesy: James Di Loreto, Smithsonian)

To Tim McCoy, Sara Russell, Danny Glavin, Jason Dworkin, Yoshihiro Furukawa, Ann Nguyen, Scott Sandford, Zack Gainsforth and an international team of collaborators for identifying salt, ammonia, sugar, nitrogen- and oxygen-rich organic materials, and traces of metal-rich supernova dust, in samples returned from the near-Earth asteroid 101955 Bennu. The incredible chemical richness of this asteroid, which NASA’s OSIRIS-REx spacecraft visited in 2020, lends support to the longstanding hypothesis that asteroid impacts could have “seeded” the early Earth with the raw ingredients needed for life to form. The discoveries also enhance our understanding of how Bennu and other objects in the solar system formed out of the disc of material that coalesced around the young Sun.

The first superfluid molecule

To Takamasa Momose of the University of British Columbia, Canada, and Susumu Kuma of the RIKEN Atomic, Molecular and Optical Physics Laboratory, Japan for observing superfluidity in a molecule for the first time. Molecular hydrogen is the simplest and lightest of all molecules, and theorists predicted that it would enter a superfluid state at a temperature between 1‒2 K. But this is well below the molecule’s freezing point of 13.8 K, so Momose, Kuma and colleagues first had to develop a way to keep the hydrogen in a liquid state. Once they did that, they then had to work out how to detect the onset of superfluidity. It took them nearly 20 years, but by confining clusters of hydrogen molecules inside helium nanodroplets, embedding a methane molecule within the clusters, and monitoring the methane’s rotation, they were finally able to do it. They now plan to study larger clusters of hydrogen, with the aim of exploring the boundary between classical and quantum behaviour in this system.

Hollow-core fibres break 40-year limit on light transmission

To researchers at the University of Southampton and Microsoft Azure Fiber in the UK, for developing a new type of optical fibre that reduces signal loss, boosts bandwidth and promises faster, greener communications. The team, led by Francesco Poletti, achieved this feat by replacing the glass core of a conventional fibre with air and using glass membranes that reflect light at certain frequencies back into the core to trap the light and keep it moving through the fibre’s hollow centre. Their results show that the hollow-core fibres exhibit 35% less attenuation than standard glass fibres – implying that fewer amplifiers would be needed in long cables – and increase transmission speeds by 45%. Microsoft has begun testing the new fibres in real systems, installing segments in its network and sending live traffic through them. These trials open the door to gradual rollout and Poletti suggests that the hollow-core fibres could one day replace existing undersea cables.

First patient treatments delivered with proton arc therapy

PAT pioneers The research team in the proton therapy gantry room. (Courtesy: UO Fisica Sanitaria and UO Protonterapia, APSS, Trento)

To Francesco Fracchiolla and colleagues at the Trento Proton Therapy Centre in Italy for delivering the first clinical treatments using proton arc therapy (PAT). Proton therapy – a precision cancer treatment – is usually performed using pencil-beam scanning to precisely paint the dose onto the tumour. But this approach can be limited by the small number of beam directions deliverable in an acceptable treatment time. PAT overcomes this by moving to an arc trajectory with protons delivered over a large number of beam angles and the potential to optimize the number of energies used for each beam direction. Working with researchers at RaySearch Laboratories in Sweden, the team performed successful dosimetric comparisons with clinical proton therapy plans. Following a feasibility test that confirmed the viability of clinical PAT delivery, the researchers used PAT to treat nine cancer patients. Importantly, all treatments were performed using the centre’s existing proton therapy system and clinical workflow.

A protein qubit for quantum biosensing

To Peter Maurer and David Awschalom at the University of Chicago Pritzker School of Molecular Engineering and colleagues for designing a protein quantum bit (qubit) that can be produced directly inside living cells and used as a magnetic field sensor. While many of today’s quantum sensors are based on nitrogen–vacancy (NV) centres in diamond, they are large and hard to position inside living cells. Instead, the team used fluorescent proteins, which are just 3 nm in diameter and can be produced by cells at a desired location with atomic precision. These proteins possess similar optical and spin properties to those of NV centre-based qubits – namely that they have a metastable triplet state. The researchers used a near-infrared laser pulse to optically address a yellow fluorescent protein and read out its triplet spin state with up to 20% spin contrast. They then genetically modified the protein to be expressed in bacterial cells and measured signals with a contrast of up to 8%. They note that although this performance does not match that of NV quantum sensors, it could enable magnetic resonance measurements directly inside living cells, which NV centres cannot do.

Highest-resolution images ever taken of a single atom

To the team led by Yichao Zhang at the University of Maryland and Pinshane Huang of the University of Illinois at Urbana-Champaign for capturing the highest-resolution images ever taken of individual atoms in a material. The team used an electron-microscopy technique called electron ptychography to achieve a resolution of 15 pm, which is about 10 times smaller than the size of an atom. They studied a stack of two atomically-thin layers of tungsten diselenide, which were rotated relative to each other to create a moiré superlattice. These twisted 2D materials are of great interest to physicists because their electronic properties can change dramatically with small changes in rotation angle. The extraordinary resolution of their microscope allowed them to visualize collective vibrations in the material called moiré phasons. These are similar to phonons, but had never been observed directly until now. The team’s observations align with theoretical predictions for moiré phasons. Their microscopy technique should boost our understanding of the role that moiré phasons and other lattice vibrations play in the physics of solids. This could lead to the engineering of new and useful materials.

Quantum control of individual antiprotons

Exquisite control Physicist Barbara Latacz at the BASE experiment at CERN. (Courtesy: CERN)

To CERN’s BASE collaboration for being the first to perform coherent spin spectroscopy on a single antiproton – the antimatter counterpart of the proton. Their breakthrough is the most precise measurement yet of the antiproton’s magnetic properties, and could be used to test the Standard Model of particle physics. The experiment begins with the creation of high-energy antiprotons in an accelerator. These must be cooled (slowed down) to cryogenic temperatures without being lost to annihilation. Then, a single antiproton is held in an ultracold electromagnetic trap, where microwave pulses manipulate its spin state. The resulting resonance peak was 16 times narrower than previous measurements, enabling a significant leap in precision. This level of quantum control opens the door to highly sensitive comparisons of the properties of matter (protons) and antimatter (antiprotons). Unexpected differences could point to new physics beyond the Standard Model and may also reveal why there is much more matter than antimatter in the visible universe.

A smartphone-based early warning system for earthquakes

To Richard Allen, director of the Berkeley Seismological Laboratory at the University of California, Berkeley, and Google’s Marc Stogaitis and colleagues for creating a global network of Android smartphones that acts as an earthquake early warning system. Traditional early warning systems use networks of seismic sensors that rapidly detect earthquakes in areas close to the epicentre and issue warnings across the affected region. Building such seismic networks, however, is expensive, and many earthquake-prone regions do not have them. The researchers utilized the accelerometer in millions of phones in 98 countries to create the Android Earthquake Alert (AEA) system. Testing the app between 2021 and 2024 led to the detection of an average of 312 earthquakes a month, with magnitudes ranging from 1.9 to 7.8. For earthquakes of magnitude 4.5 or higher, the system sent “TakeAction” alerts to users, sending them, on average, 60 times per month for an average of 18 million individual alerts per month. The system also delivered lesser “BeAware” alerts to regions expected to experience a shaking intensity of magnitude 3 or 4. The team now aims to produce maps of ground shaking, which could assist the emergency response services following an earthquake.

A “weather map” for a gas giant exoplanet

To Lisa Nortmann at Germany’s University of Göttingen and colleagues for creating the first detailed “weather map” of an exoplanet. The forecast for exoplanet WASP-127b is brutal with winds reaching 33,000 km/hr, which is much faster than winds found anywhere in the Solar System. The WASP-127b is a gas giant located about 520 light–years from Earth and the team used the CRIRES+ instrument on the European Southern Observatory’s Very Large Telescope to observe the exoplanet as it transited across its star in less than 7 h. Spectral analysis of the starlight that filtered through WASP-127b’s atmosphere revealed Doppler shifts caused by supersonic equatorial winds. By analysing the range of Doppler shifts, the team created a rough weather map of WASP-127b, even though they could not resolve light coming from specific locations on the exoplanet. Nortmann and colleagues concluded that the exoplanet’s poles are cooler that the rest of WASP-127b, where temperatures can exceed 1000 °C. Water vapour was detected in the atmosphere, raising the possibility of exotic forms of rain.

Physics World‘s coverage of the Breakthrough of the Year is supported by Reports on Progress in Physics, which offers unparalleled visibility for your ground-breaking research.

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How to make 2D metals: Guangyu Zhang on his team’s award-winning research

Hamish Johnston — Thu, 18 Dec 2025 14:13:52 +0000

This episode of the Physics World Weekly podcast features Guangyu Zhang. Along with his colleagues at the Institute of Physics of the Chinese Academy of Sciences, Zhang has bagged the 2025 Physics World Breakthrough of the Year award for creating the first 2D metals.

In a wide-ranging conversation, we chat about the motivation behind the team’s research; the challenges in making 2D metals and how these were overcome; and how 2D metals could be used to boost our understanding of condensed matter physics and create new technologies.

I am also joined by my Physics World colleague Matin Durrani to talk about some of the exciting physics that we will be showcasing in 2025.

Physics World‘s coverage of the Breakthrough of the Year is supported by Reports on Progress in Physics, which offers unparalleled visibility for your ground-breaking research.

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Quantum cluster targets business growth

No Author — Thu, 18 Dec 2025 12:52:22 +0000

Julia Sutcliffe (second from the left), Chief Scientific Advisor for the UK’s Department for Business and Trade, visits the NQCC’s experimental facilities on the Harwell Cluster (Courtesy: NQCC)

Ever since the National Quantum Computing Centre was launched five years ago, its core mission has been to accelerate the pathway towards practical adoption of the technology. That has required technical innovation to scale up hardware platforms and create the software tools and algorithms needed to tackle real-world applications, but there has also been a strong focus on engaging with companies to build connections, provide access to quantum resources, and identify opportunities for deriving near-term value from quantum computing.

It makes sense, then, that the NQCC should form the cornerstone of a new Quantum Cluster at the Harwell Campus of Science and Innovation in Oxfordshire. The hope is that the NQCC’s technical expertise and infrastructure, combined with the services and facilities available on the wider Harwell Campus, will provide a magnet for new quantum start-ups as well as overseas companies that are seeking to establish a presence within the UK’s quantum ecosystem.

By accelerating collaboration across government, industry and academia, we will turn research excellence into industrial strength.

“We want to leverage the public investment that has been made into the NQCC to catalyse business growth and attract more investment into the UK’s quantum sector,” said Najwa Sidqi, manager of the Harwell Quantum Cluster, at the official launch event in November. “By accelerating collaboration across government, industry and academia, we will turn research excellence into industrial strength.”

The cluster, which has been ramping up its activities over the last year, is working to ambitious targets. Over the next decade the aim is to incubate at least 100 quantum companies on the Harwell site, create more than 1000 skilled jobs, and generate more than £1 billion of private and public investment. “Our aim is to build the foundations of a globally competitive quantum economy that delivers impact far beyond science and research,” added Sidqi.

Tangible evidence that the approach works is offered by the previous clustering activities on the Harwell Campus, notably the Space Cluster that has expanded rapidly since its launch in 2010. Anchored by the RAL Space national laboratory and bolstered by the presence of ESA and the UK Space Agency, the Space Cluster now comprises more than 100 organizations that range from small start-ups to the UK technology hubs of global heavyweights such as Airbus and Lockheed Martin.

More generally, the survival rate of start-up companies operating on the Harwell site is around 95%, compared with an average of around 50%. “At Harwell there is a high density of innovators sharing the same space, which generates more connections and more ideas,” said Julia Sutcliffe, Chief Scientific Advisor for the UK’s Department for Business and Trade. “It provides an incredible combination of world-class infrastructure and expertise, accelerating the innovation pathway and helping to create a low-risk environment for early-stage businesses and investors.”

The NQCC has already seeded that innovation activity through its early engagement with both quantum companies and end users of the technology. One major initiative has been the testbed programme, which has enabled the NQCC to invest £30m in seven hardware companies to deploy prototype quantum computers on the Harwell Campus. As well as providing access to operational systems based on all of the leading qubit modalities, the testbed programme has also provided an impetus for inward investment and job creation.

One clear example is provided by QuEra Computing, a US-based spin-off from Harvard University and the Massachusetts Institute of Technology that is developing a hardware platform based on neutral atoms. QuEra was one of the companies to win funding through the testbed programme, with the firm setting up a UK-based team to deploy its prototype system on the Harwell Campus. But the company could soon see the benefits of establishing a UK centre for technology development on the site. “Harwell is immensely helpful to us,” said Ed Durking, Corporate Director of QuEra Computing UK. “It’s a nucleus where we enjoy access to world-class talent, vendors, customers, and suppliers.”

On a practical level, establishing its UK headquarters on the Harwell Campus has provided QueEra with easy access to specialist contractors and services for fitting out and its laboratories. In June the company moved into a building that is fully equipped with flexible lab space for R&D and manufacturing, and since then the UK-based team has started to build the company’s most powerful quantum computer at the facility. Longer term, establishing a base within the UK could open the door to new collaborations and funding opportunities for QuEra to further develop its technology, with the company now focused on integrating full error correction into its neutral-atom platform by 2026.

Access to the world-class infrastructure on the Harwell Campus has benefitted the other testbed providers in different ways. For ORCA Computing, a UK company developing and manufacturing photonic quantum computers, the goal was to install a testbed system within Harwell’s high-performance computing centre rather than the NQCC’s experimental labs. “Our focus is to build commercial photonic quantum systems that can be integrated into conventional datacentres, enabling hybrid quantum-classical workflows for real-world applications,” explained Geoff Barnes, Head of Customer Success at ORCA. “Having the NQCC as an expert customer enabled us to demonstrate and validate our capabilities, building the system in our own facility and then deploying it within an operational environment.”

This process provided a valuable learning experience for the ORCA engineers. The experts at Harwell helped them to navigate the constraints of installing equipment within a live datacentre, while also providing practical assistance with the networking infrastructure. Now that the system is up and running, the Harwell site also provides ORCA with an open environment for showcasing its technology to prospective customers. “As well as delivering a testbed system to the NQCC, we can now demonstrate our platform to clients within a real-world setting,” added Barnes. “It has also been a critical step toward commercial deployment on our roadmap, enabling our partners to access our systems remotely for applications development.”

Michael Cuthbert (left), Director of the NQCC, takes Sutcliffe and other visitors on a tour of the national lab (Courtesy: NQCC)

While the NQCC has already played a vital role in supporting companies as they make the transition towards commercialization, the Quantum Cluster has a wider remit to extend those efforts into other quantum technologies, such as sensing and communications, that are already finding real-world applications. It will also have a more specific focus on attracting new investment into the UK, and supporting the growth of companies that are transitioning from the start-up phase to establish larger scale commercial operations.

“In the UK we have traditionally been successful in creating spin-off activities from our strong research base, but it has been more challenging to generate the large capital investments needed to scale businesses in the technology sector,” commented Sidqi. “We want to strengthen that pipeline to ensure that the UK can translate its leadership in quantum research and early-stage innovation into long-term prosperity.”

To accelerate that process the Quantum Cluster announced a strategic partnership with Quantum Exponential, the first UK-based venture capital fund to be entirely focused on quantum technologies. Ian Pearson, the non-executive chairman of the Quantum Exponential, explained that the company is working to generate an investment fund of £100m by the end of 2027 that will support quantum companies as they commercialize their technologies and scale up their businesses. “Now is the time for investment into quantum sector,” said Pearson. “A specialist quantum fund with the expertise needed to analyse and price deals, and to do all the necessary due diligence, will attract more private investment that will help UK companies to grow and scale.”

Around two-thirds of the investments will be directed towards UK-based companies, and as part of the partnership Quantum Exponential will work with the Quantum Cluster to identify and support high-potential quantum businesses within the Harwell Campus. The Quantum Cluster will also play a crucial role in boosting investor confidence – particularly in the unique ability of the Harwell Campus to nurture successful technology businesses – and making connections with international innovation networks to provide UK-based companies with improved access to global markets.

“This new cluster strengthens our national capability and sends a clear signal to global investors that the UK is the place to develop and scale quantum technologies,” commented Michael Cuthbert, Director of the NQCC. “It will help to ensure that quantum innovation delivers benefits not just for science and industry, but for the economy and society as a whole.”

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Transparent and insulating aerogel could boost energy efficiency of windows

No Author — Thu, 18 Dec 2025 12:07:46 +0000

An aerogel material that is more than 99% transparent to light and is an excellent thermal insulator has been developed by Ivan Smalyukh and colleagues at the University of Colorado Boulder in the US. Called MOCHI, the material can be manufactured in large slabs and could herald a major advance in energy-efficient windows.

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While the insulating properties of building materials have steadily improved over the past decades, windows have consistently lagged behind. The problem is that current materials used in windows – mostly glass – have an inherent trade-off between insulating ability and optical transparency. This is addressed to some extent by using two or three layers of glass in double- and triple-glazed windows. However, windows remain the largest source of heat loss from most buildings.

A solution to the window problem could lie with aerogels in which the liquid component of a regular gel is replaced with air. This creates solid materials with networks of pores that make aerogels the lightest solid materials ever produced. If the solid component is a poor conductor of heat, then the aerogel will be an extremely good thermal insulator.

“Conventional aerogels, like the silica and cellulose based ones, are common candidates for transparent, thermally insulating materials,” Smalyukh explains. “However, their visible-range optical transparency is intrinsically limited by the scattering induced by their polydisperse pores – which can range from nanometres to micrometres in scale.”

Hazy appearance

While this problem can be overcome fairly easily in thin aerogel films, creating appropriately-sized pores on the scale of practical windows has so far proven much more difficult, leading to a hazy, translucent appearance.

Now, Smalyukh’s team has developed a new fabrication technique involving a removable template. Their approach hinges on the tendency of surfactant molecules called CPCL to self-assemble in water. Under carefully controlled conditions, the molecules spontaneously form networks of cylindrical tubes, called micelles. Once assembled, the aerogel precursor – a silicone material called polysiloxane – condenses around the micelles, freezing their structure in place.

“The ensuing networks of micelle-templated polysiloxane tubes could be then preserved upon the removal of surfactant, and replacing the fluid solvent with air,” Smalyukh describes. The end result was a consistent mesoporous structure, with pores ranging from 2–50 nm in diameter. This is too small to scatter visible light, but large enough to interfere with heat transport.

As a result, the mesoporous, optically clear heat insulator (MOCHI) maintains its transparency even when fabricated in slabs over 3 cm thick and a square metre in area. This suggests that it could be used to create practical windows.

High thermal performance

“We demonstrated thermal conductivity lower than that of still air, as well as an average light transmission above 99%,” Smalyukh says. “Therefore, MOCHI glass units can provide a similar rate of heat transfer to high-performing building roofs and walls, with thicknesses comparable to double pane windows.”

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If rolled out on commercial scales, this could lead to entirely new ways to manage interior heating and cooling. According to the team’s calculations, a building retrofitted with MOCHI windows could boost its energy efficiency from around 6% (a typical value in current buildings) to over 30%, while reducing the heat energy passing through by around 50%.

With its ability to admit light while blocking heat transport, the researchers suggest that MOCHI could unlock entirely new functionalities for conventional windows. “Such transparent insulation also allows for efficient harnessing of thermal energy from unconcentrated solar radiation in different climate zones, promising the use of parts of opaque building envelopes as solar thermal energy generating panels,” Smalyukh adds.

The new material is described in Science.

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Qubit ‘recycling’ gives neutral-atom quantum computing a boost

Anna Demming — Thu, 18 Dec 2025 09:00:25 +0000

Errors are the bugbear of quantum computing, and they’re hard to avoid. While quantum computers derive their computational clout from the fact that their qubits can simultaneously court multiple values, the fragility of qubit states ramps up their error rates. Many research groups are therefore seeking to reduce or manage errors so they can increase the number of qubits without reducing the whole enterprise to gibberish.

A team at the US-based firm Atom Computing is now reporting substantial success in this area thanks to a multi-part strategy for keeping large numbers of qubits operational in quantum processors based on neutral atoms. “These capabilities allow for the execution of more complex, longer circuits that are not possible without them,” says Matt Norcia, one of the Atom Computing researchers behind this work.

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While neutral atoms offer several advantages over other qubit types, they traditionally have significant drawbacks for one of the most common approaches to error correction. In this approach, some of the entangled qubits are set aside as so-called “ancillaries”, used for mid-circuit measurements that can indicate how a computation is going and what error correction interventions may be necessary.

In neutral-atom quantum computing, however, such interventions are generally destructive. Atoms that are not in their designated state are simply binned off – a profligate approach that makes it challenging to scale up atom-based computers. The tendency to discard atoms is particularly awkward because the traps that confine atoms are already prone to losing atoms, which introduces additional errors while reducing the number of atoms available for computations.

Reduce, re-use, replenish

As well as demonstrating protocols for performing measurements to detect errors in quantum circuits with little atom loss, the researchers at Atom Computing also showed they could re-use ancillary atoms – a double-pronged way of retaining more atoms for calculations. In addition, they demonstrated that they could replenish the register of atoms for the computation from a spatially separated stash in a magneto-optic trap without compromising the quantum state of the atoms already in the register.

Norcia says that these achievements — replacing atoms from a continuous source, while reducing the number of atoms needing replacement to begin with — are key to running computations without running out of atoms. “To our knowledge, any useful quantum computations will require the execution of many layers of gates, which will not be possible unless the atom number can be maintained at a steady-state level throughout the computation,” he tells Physics World.

Cool and spaced out

Norcia and his collaborators at Microsoft Quantum, the Colorado School of Mines and Stanford University worked with ytterbium (Yb) atoms, which he describes as “natural qubits” since they have two ground states. A further advantage is that the transitions between these qubit states and other states used for imaging and cooling are weak, meaning the researchers could couple just one qubit state to these other states at a time. The team also leveraged a previously-developed approach for mid-circuit measurement that scatters light from only one qubit state and does not disturb the other, making it less destructive.

Still, Norcia tells Physics World, “the challenge was to re-use atoms, and key to this was cooling and performance.” To this end, they first had to shift the atoms undergoing mid-circuit measurements away from the atoms in the computational register, to avoid scattering laser light off the latter. They further avoided laser-related collateral damage by designing the register such that the measurement and cooling light was not at the resonant wavelength of the register atoms. Next, they demonstrated they could cool already-measured atoms for re-use in the calculation. Finally, they showed they could non-disruptively replenish these atoms with others from a magneto-optical trap positioned 300 nm below the tweezer arrays that held atoms for the computational register.

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Mikhail Lukin, a physicist at Harvard University, US who has also worked on the challenges of atom loss and re-use in scalable, fault-tolerant neutral atom computing, has likewise recently reported successful atom re-use and diminished atom loss. Although Lukin’s work differs from that of the Atom Computing team in various ways – using rubidium instead of ytterbium atoms and a different approach for low atom loss mid-circuit measurements, for starters – he says that the work by Norcia and his team “represents an important technical advance for the Yb quantum computing platform, complementing major progress in the neutral atom quantum computing community in 2025”.

The research appears in Physical Review X.

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Forging a more inclusive new generation of physicists

James Dacey — Wed, 17 Dec 2025 18:00:50 +0000

The latest episode of Physics World Stories takes you inside CUWiP+, the Conference for Undergraduate Women and Non-Binary Physicists, and the role the annual event plays in shaping early experiences of studying physics.

The episode features June McCombie from the University of Nottingham, who discusses what happens at CUWiP+ events and why they are so important for improving the retention of women and non-binary students in STEM. She reflects on how the conferences create space for students to explore career paths, build confidence and see themselves as part of the physics community.

Reflections and tips from CUWiP+ 2025

University of Birmingham students Tanshpreet Kaur and Harriett McCormick share their experiences of attending the 2025 CUWiP+ event at the University of Warwick and explain why they are excited for the next event, set for Birmingham, 19–22 March 2026. They describe standout moments from 2025, including being starstruck at meeting Dame Jocelyn Bell Burnell, who discovered radio pulsars in 1967.

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The episode provides practical advice to get the most out of the event. Organizers design the programme to cater for all personalities – whether you thrive in lively, social situations, or prefer time to step back and reflect. Either way, CUWiP+ offers opportunities to be inspired and to make meaningful connections.

Hosted by Andrew Glester, the episode highlights how shared experiences and supportive networks can balance the often-solitary nature of studying physics, especially when you feel excluded from the majority group.

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Learning through laughter at Quantum Carousel

No Author — Wed, 17 Dec 2025 16:00:24 +0000

Quantum physics, kung-fu, LEGO and singing are probably not things you would normally put together. But that’s exactly what happened at this year’s Quantum Carousel.

The event is a free variety show where incredible performers from across academia and industry converge for an evening of science communication. Held in Bristol, UK, on 14 November 2025, this was the second year the event was run – and once again it was entirely sold out.

As organizers, our goal was to bring together those involved in quantum and adjacent fields for an evening of learning and laughter. Each act was only seven minutes long and audience participation was encouraged, with questions saved for the dinner and drinks intervals.

All together now Speakers at Quantum Carousel 2025, which was organized by Zulekha Samiullah (second from right) and Hugh Barrett (far right). (Courtesy: Yolan Ankaine)

The evening kicked off with a rousing speech and song from Chris Stewart, motivating the promotion of science communication and understanding. Felix Flicker related electron spin rotations to armlocks, with a terrific demonstration on volunteer Tony Short, while Michael Berry entertained us all with his eye-opening talk on how quantum physics has democratized music.

PhD student double act Eesa Ali and Sebastien Bisdee then welcomed volunteers to the stage to see who could align a laser fastest. Maria Violaris expertly taught us the fundamentals of quantum error correction using LEGO.

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Mike Shubrook explained the quantum thermodynamics of beer through stand-up comedy. And finally, John Rarity and his assistant Hugh Barrett (event co-organizer and co-author of this article) rounded off the night by demonstrating the magic of entanglement.

Our event sponsors introduced the food and drinks portions of the evening, with Antonia Seymour (chief executive of IOP Publishing) and Matin Durrani (editor-in-chief of Physics World) opening the dinner interval, while Josh Silverstone (founder and chief executive of Hartley Ultrafast) kickstarted the networking drinks reception.

Singing praises

Whether it was singing along to an acoustic guitar or rotating hands to emulate electron spin, everyone got involved, and feedback cited audience participation as a highlight.

“The event ran very smoothly, it was lots of fun and a great chance to network in a relaxed atmosphere,” said one attendee. Another added: “The atmosphere was really fun, and it was a really nice event to get loads of the quantum community together in an enjoyable setting.”

Appreciation of the atmosphere went both ways, with one speaker saying that their favourite part of the night was that “the audience was very inviting and easy to perform to”.

Audience members also enjoyed developing a better understanding of the science that drives their industry. “I understood it and I don’t have any background in physics,” said one attendee. “I feel a marker of being a good scientist is being able to explain it in layperson’s terms.”

Reaching out

With the quantum community rapidly expanding, it needs people from a wide range of backgrounds such as computer science, engineering and business. Quantum Carousel was designed to strike a balance between high-level academic discussion and entertainment through entry-level talks, such as explaining error correction with props, or relating research to impact from stimulated emission to CDs.

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By focusing on real-world analogies, these talks can help newcomers to develop an intuitive and memorable understanding. Meanwhile, those already in the field can equip themselves with new ways of communicating elements of their research.

We look forward to hosting Quantum Carousel again in the future. We want to make it bigger and better, with an even greater range of diverse acts.

But if you’re interested in organizing a similar outreach event of your own, it helps to consider how you can create an environment that can best spark connections between both speakers and attendees. Consider your audience and how your event can attract different people for different reasons. In our case, this included the chance to network, engage with the performances, and enjoy the food and drink.

Quantum Carousel was founded by Zulekha Samiullah in 2024, and she and Hugh Barrett now co-lead the event. Quantum Carousel 2025 was sponsored by the QE-CDT, IOP Publishing and Hartley Ultrafast.

This article forms part of Physics World‘s contribution to the 2025 International Year of Quantum Science and Technology (IYQ), which aims to raise global awareness of quantum physics and its applications.

Stayed tuned to Physics World and our international partners throughout the year for more coverage of the IYQ.

Find out more on our quantum channel.

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Korea’s long-term strategy for 2D materials: fundamental science is the secret of success

No Author — Wed, 17 Dec 2025 15:03:17 +0000

Scaling up The IBS Center for Van der Waals Quantum Solids (IBS-VdWQS) acts as a catalyst for advances in fundamental materials science and condensed-matter physics. The purpose-built facility is colocated on the campus of POSTECH, one of Korea’s leading universities. (Courtesy: IBS)

What’s the research mission of the IBS Center for Van der Waals Quantum Solids (IBS-VdWQS)?

Our multidisciplinary team aims to create heteroepitaxial van der Waals quantum solids at system scales, where the crystal lattices and symmetries of these novel 2D materials are artificially moulded to atomic precision via epitaxial growth. Over time, we also hope to translate these new solids into quantum device platforms.

Clearly there’s all sorts of exotic materials physics within that remit.

Correct. We form van der Waals heterostructures by epitaxial manipulation of the crystal lattice in diverse, atomically thin 2D materials – for example, 2D heterostructures incorporating graphene, boron nitride or transition-metal dichalcogenides (such as MoS₂, WSe₂, NbSe₂, TaSe₂and so on). Crucially, the material layers are held in place only by weak van der Waals forces and with no dangling chemical bonds in the direction normal to the layers.

These 2D layers can also be laterally “stitched” into hexagonal or honeycomb lattices, with the electronic and atomic motions confined into the atomic layers. Using state-of-the-art epitaxial techniques, our team can then artificially stack these lattices to form a new class of condensed matter with exotic interlayer couplings and emergent electronic, optical and magnetic properties – properties that, we hope, will find applications in next-generation quantum devices.

The IBS-VdWQS is part of Korea’s Institute for Basic Science (IBS). How does this arrangement work?

Moon-Ho Jo “While the focus is very much on basic science, epitaxial scalability is hard-wired into all our lines of enquiry.” (Courtesy: IBS)

The IBS headquarters was established in 2011 as Korea’s first dedicated institute for fundamental science. It’s an umbrella organization coordinating the activity of 38 centres-of-excellence across the physical sciences, life sciences, as well as mathematics and data science. In this way, IBS specializes in long-range initiatives that require large groups of researchers from Korea and abroad.

Our IBS-VdWQS is a catalyst for advances in fundamental materials science and condensed-matter physics, essentially positioned as a central-government-funded research institution in a research-oriented university. Particularly important in this regard is our colocation on the campus of Pohang University of Science and Technology (POSTECH), one of Korea’s leading academic centres, and our adjacency to large-scale facilities like the Pohang Synchrotron Radiation Facility (PAL) and Pohang X-ray free-electron laser (PAL-XFEL). It’s worth noting as well that all the principal investigators (PIs) in our centre hold dual positions as IBS researchers and POSTECH professors.

So IBS is majoring on strategic research initiatives?

Absolutely – and that perspective also underpins our funding model. The IBS-VdWQS was launched in 2022 and is funded by IBS for an initial period through to 2032 (with a series of six-year extensions subject to the originality and impact of our research). As such, we are able to encourage autonomy across our 2D materials programme, giving scientists the academic freedom to pursue questions in basic research without the bureaucracy and overhead of endless grant proposals. Team members know that, with plenty of hard work and creativity, they have everything they need here to do great science and build their careers.

Your core remit is fundamental science, but what technologies could eventually emerge from the IBS-VdWQS research programme?

While the focus is very much on basic science, epitaxial scalability is hard-wired into all our lines of enquiry. In short: we are creating new 2D materials via epitaxial growth and this ultimately opens a pathway to wafer-scale industrial production of van der Waals materials with commercially interesting semiconducting, superconducting or emergent properties in general.

Right now, we are investigating van der Waals semiconductors and the potential integration of MoS₂ and WSe₂ with silicon for new generations of low-power logic circuitry. On a longer timeline, we are developing new types of high-Tc (around 10 K) van der Waals superconductors for applications in Josephson junctions, which are core building blocks in superconducting quantum computers.

There’s a parallel opportunity in photonic quantum computing, with van der Waals materials shaping up as promising candidates for quantum light-emitters that generate on-demand (deterministic) and highly coherent (indistinguishable) single-photon streams.

Establishing a new research centre from scratch can’t have been easy. How are things progressing?

It’s been a busy three years since the launch of the IBS-VdWQS. The most important task at the outset was centralization – pulling together previously scattered resources, equipment and staff from around the POSTECH campus. We completed the move into our purpose-built facility, next door to the PAL synchrotron light source, at the end of last year and have now established dedicated laboratory areas for the van der Waals Epitaxy Division; Quantum Device and Optics Division; Quantum Device Fabrication Division; and the Imaging and Spectroscopy Division.

One of our front-line research efforts is building a van der Waals Quantum Solid Cluster, an integrated system of multiple instruments connected by ultra-high-vacuum lines to maintain atomically clean surfaces. We believe this advanced capability will allow us to reliably study air-sensitive van der Waals materials and open up opportunities to discover new physics in previously inaccessible van der Waals platforms.

Integrated thinking The IBS-VdWQS hosts an end-to-end research programme spanning advanced fabrication, materials characterization and theoretical studies. From left to right: vapour-phase van der Waals crystal growth; femtosecond laser spectroscopy for studying ultrafast charge, spin and lattice dynamics; and an STM system for investigations of electronic structure and local quantum properties in van der Waals materials. (Courtesy: IBS)

Are there plans to scale the IBS-VdWQS work programme?

Right now, my priority is to promote opportunities for graduate students, postdoctoral researchers and research fellows to accelerate the centre’s expanding research brief. Diversity is strength, so I’m especially keen to encourage more in-bound applications from talented experimental and theoretical physicists in Europe and North America. Our current research cohort comprises 30+ PhD students, seven postdocs (from the US, India, China and Korea) and seven PIs.

Over the next five years, we aim to scale up to 25+ postdocs and research fellows and push out in new directions such as scalable quantum devices. In particular, we are looking for scientists with specialist know-how and expertise in areas like materials synthesis, quantum transport, optical spectroscopy and scanning probe microscopy (SPM) to accelerate our materials research.

How do you support your early-career researchers at IBS-VdWQS?

We are committed to nurturing global early-career talent and provide a clear development pathway from PhD through postdoctoral studies to student research fellow and research fellow/PI. Our current staff PIs have diverse academic backgrounds – materials science, physics, electronic engineering and chemistry – and we therefore allow early-career scientists to have a nominated co-adviser alongside their main PI. This model means research students learn in an integrated fashion that encourages a “multidisciplinarian” mindset – majoring in epitaxial growth, low-temperature electronic devices and optical spectroscopy, say, while also maintaining a watching brief (through their co-adviser) on the latest advances in materials characterization and analysis.

What does success look like at the end of the current funding cycle?

With 2032 as the first milestone year in this budget cycle, we are working to establish a global hub for van der Waals materials science – a highly collaborative and integrated research programme spanning advanced fabrication, materials characterization/analysis and theoretical studies. More capacity, more research infrastructure, more international scientists are all key to delivering our development roadmap for 2D semiconductor and superconductor integration towards scalable, next-generation low-power electronics and quantum computing devices.

Find more information on open research positions at IBS-VdWQS.

Building a scientific career in 2D materials

Myungchul Oh “We are exploring the microscopic nature of quantum materials and their device applications.” (Courtesy: IBS)

Myungchul Oh joined the IBS-VdWQS in 2023 after a five-year stint as a postdoctoral physicist at Princeton University in the US, where he studied strongly correlated phenomena, superconductivity and topological properties in “twisted” graphene systems.

Recruited as an IBS-POSTECH research fellow, Oh holds dual academic positions: team leader for the quantum-device microscopy investigations at IBS-VdWQS and assistant professor in the semiconductor engineering department at POSTECH.

Van der Waals heterostructures, assembled layer-by-layer from 2D materials, enable precise engineering of quantum properties through the interaction between different atomic layers. By extension, Oh and his colleagues are focused on the development of novel van der Waals systems; their integration into devices via nanofabrication; and the study of electrical, magnetic and topological properties under extreme conditions, where quantum-mechanical effects dominate.

“We are exploring the microscopic nature of quantum materials and their device applications,” Oh explains. “Our research combines novel 2D van der Waals heterostructure device fabrication techniques with cryogenic scanning probe microscopy (SPM) measurements – the latter to access the atomic-scale electronic structure and local physical properties of quantum phases in 2D materials.”

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Atomic system acts like a quantum Newton’s cradle

No Author — Wed, 17 Dec 2025 11:15:48 +0000

Atoms in a one-dimensional quantum gas behave like a Newton’s cradle toy, transferring energy from atom to atom without dissipation. Developed by researchers at the TU Wien, Austria, this quantum fluid of ultracold, confined rubidium atoms can be used to simulate more complex solid-state systems. By measuring transport quantities within this “perfect” atomic system, the team hope to obtain a deeper understanding of how transport phenomena and thermodynamics behave at the quantum level.

Physical systems transport energy, charge and mass in various ways. Electrical currents streaming along a wire, heat flowing through a solid and light travelling down an optical fibre are just three examples. How easily these quantities move inside a material depends on the resistance they experience, with collisions and friction slowing them down and making them fade away. This level of resistance largely determines whether the material is classed as an insulator, a conductor or a superconductor.

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The mechanisms behind such transport fall into two main categories. The first is ballistic transport, which features linear movement without loss, like a bullet travelling in a straight line. The second is diffusive transport, where the quantity is subject to many random collisions. A good example is heat conduction, where the heat moves through a material gradually, travelling in many directions at once.

Breaking the rules

Most systems are strongly affected by diffusion, which makes it surprising that the TU Wien researchers could build an atomic system where mass and energy flowed freely without it. According to study leader Frederik Møller, the key to this unusual behaviour is the magnetic and optical fields that keep the rubidium atoms confined to one dimension, “freezing out” interactions in the atoms’ two transverse directions.

Because the atoms can only move along a single direction, Møller explains, they transfer momentum perfectly, without scattering their energy as would be the case in normal matter. Consequently, the 1D atomic system does not thermalize despite being subject to thousands of collisions.

To quantify the transport of mass (charge) and energy within this system, the researchers measured quantities known as Drude weights, which are fundamental parameters that describe ballistic, dissipationless transport in solid-state environments. According to these measurements, the single-dimensional interacting bosonic atoms do indeed demonstrate perfect dissipationless transport. The results also agree with the generalized hydrodynamics (GHD) theoretical framework, which describes the large-scale, inhomogeneous dynamics of one-dimensional integrable quantum many-body systems such as ultracold atomic gases or specific spin chains.

A Newton’s cradle for atoms

According to team leader Jörg Schmiedmayer, the experiment is analogous to a Newton’s cradle toy, which consists of a row of metal balls suspended on wires (see below). When the ball on one end of the row is made to collide with the one next to it, its momentum transfers straight through the other balls to the ball on the opposite end, which swings out. Schmiedmayer adds that the system makes it possible to study transport under perfectly controlled conditions and could open new ways of understanding how resistance emerges, or disappears, at the quantum level. “Our next steps are applying the method to strongly correlated transport and to transport in a topological fluid,” he tells Physics World.

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Karèn Kheruntsyan, a theoretical physicist at the University of Queensland, Australia, who was not involved in this research, calls it “a significant step for studying quantum transport”. He says the team’s work clearly demonstrates ballistic (dissipationless) transport at a finite temperature, providing an experimental benchmark for theories of integrability and disorder. The work also validates the thermodynamic meaning of Drude weights, while confirming that linear-response theory and GHD accurately describe transport in quantum systems.

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In Kheruntsyan’s view, though, the team’s biggest achievement is the quantitative extraction of Drude weights that characterize atomic and energy currents, with “excellent agreement” between experiment and theory. This, he says, shows truly ballistic transport in an interacting many-body system. One caveat, though, is that the system’s limited spatial resolution and near-ideal integrability prevent it from being used to explore diffusive regimes or stronger interaction effects, leaving microscopic dynamics such as dispersive shock waves unresolved.

The study is published in Science.

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Want a strong future for physics? Here’s why we must focus on students from under-represented groups

No Author — Wed, 17 Dec 2025 11:00:50 +0000

Physics students from under-represented groups consistently report a lower sense of belonging at university than their over-represented peers. These students experience specific challenges that make them feel undervalued and excluded. Yet a strong sense of belonging has been shown to lead to improved academic performance, greater engagement in courses and better mental wellbeing. It is vital, then, that universities make changes to help eliminate these challenges.

Students are uniquely placed to describe the issues when it comes to belonging in physics. With this mind, as an undergraduate physics student with a passion for making the discipline more diverse and inclusive, I conducted focus groups with current and former physics students, interviewed experts and performed an analysis of current literature. This was part of a summer project funded by the Royal Institution and is currently being finalized for publication.

From this work it became clear that under-represented groups face many challenges to developing a strong sense of belonging in physics, but, at the same time, there are ways to improve the everyday experiences of students. When it comes to barriers, one is the widely held belief – reflected in the way physicists are depicted in the media and textbooks – that you need to be a “natural genius” to succeed in university physics. This notion hampers students from under-represented groups, who see peers from the over-represented majority appearing to grasp concepts more quickly and lecturers suggesting certain topics are “easy”.

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The feeling that physics demands natural ability also arises from the so-called “weed out” culture, which is defined as courses that are intentionally designed to filter students out, reduce class sizes and diminish sense of belonging. Students who we surveyed believe that the high fail rate is caused by a disconnect between the teaching and workshops on the course and the final exam.

A third cause of this perception that you need some innate ability to succeed in physics is the attitudes and behaviour of some professors, lecturers and demonstrators. This includes casual sexist and racist behaviour; belittling students who ask for help; and acting as if they’re uninterested in teaching. Students from under-represented groups report significantly lower levels of respect and recognition from instructors, which damages their resilience and weakens sense of belonging.

Students from under-represented groups are also more likely to be isolated from their class mates and feel socially excluded from them. This means they lack a support network, leaving them with no-one to turn to when they encounter challenges. Outside the lecture theatre, students from under-represented groups typically face many microaggressions in their day-to-day university experience. These are subtle indignities or insults, unconsciously or consciously, towards minorities such as people of colour being told they “speak English very well”, male students refusing to accept women’s ideas, and the assumption that gender minorities will take on administrative roles in group projects.

Focus on the future

So what can be done? The good news is that there are many solutions to mitigate these issues and improve a sense of belonging. First, institutions should place more emphasis on small group “active learning” – which includes discussions, problem solving and peer-based learning. These pedagogical strategies have been shown to boost belonging, particularly for female students. After these active-learning sessions, non-academic, culturally sensitive social lunches can help turn “course friends” to “real friends” who choose to meet socially and can become a support network. This can help build connections within and between degree cohorts.

Another solution is for universities to invite former students to speak about their sense of belonging and how it evolved or improved throughout their degree. Hearing about struggles and learning tried-and-tested strategies to improve resilience can help students better prepare for stressful situations. Alumni are more relatable than generic messaging from the university wellbeing team.

Building closer links between students and staff also enhances a sense of belonging. It helps humanise lecturers and demonstrate that staff care about student wellbeing and success. This should be implemented by recognizing staff efforts formally so that the service roles of faculty members are formally recognized and professionalized.

Universities should also focus on hiring more diverse teaching staff, who can serve as role models, using their experiences to relate to and engage with under-represented students. Students will end up feeling more embedded within the physics community, improving both their sense of belonging and performance.

One practical way to increase diversity in hiring is for institutions to re-evaluate what they value. While securing large grants is valuable, so is advocating for equality, diversity and inclusion; public engagement; and the ability to inspire the next generation of physicists.

Another approach is to establish “departmental action teams” to find tailored solutions to unite undergraduates, postgraduates, teaching and research staff. Such teams identify issues specific to their particular university, and they can gather data through surveying the department to identify trends and recommend practical changes to boost belonging.

Implementing these measures will not only improve the sense of belonging for students from under-represented groups but also cultivate a more inclusive, diverse physics workforce. That in turn will boost the overall research culture, opening up research directions that may have previously been overlooked, and yielding stronger scientific outputs. It is crucial that we do more to support physics students from under-represented groups to create a more diverse physics community. Ultimately, it will benefit physics and society as a whole.

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Improving precision in muon g-2 calculations

Lorna Brigham — Wed, 17 Dec 2025 08:16:58 +0000

The gyromagnetic ratio is the ratio of a particle’s magnetic moment and its angular momentum. This value determines how a particle responds to a magnetic field. According to classical physics, muons should have a gyromagnetic ratio equal to 2. However, owing to quantum mechanics, there is a small difference between the expected gyromagnetic ratio and the observed value. This discrepancy is known as the anomalous magnetic moment.

The anomalous magnetic moment is incredibly sensitive to quantum fluctuations. It can be used to test the Standard Model of physics, and previous consistent experimental discrepancies have hinted at new physics beyond the Standard Model. The search for the anomalous magnetic moment is one of the most precise tests in modern physics.

To calculate the anomalous magnetic moment, experiments such as Fermilab’s Muon g-2 experiment have been set up where researchers measure the muon’s wobble frequency, which is caused by its magnetic moment. But effects such as hadronic vacuum polarization and hadronic light-by-light scattering cause uncertainty in the measurement. Unlike hadronic vacuum polarization, hadronic light-by-light cannot be directly extracted from experimental cross-section data, making it dependent on the model used and a significant computational challenge.

In this work, the researcher took a major step in resolving the anomalous magnetic moment of the muon. Their method calculated how the neutral pion contributes to hadronic light-by-light scattering, used domain wall fermions to preserve symmetry, employed eight different lattice configurations with variational pion masses, and introduced a pion structure function to find the key contributions in a model-independent method. The pion transition form factor was computed directly at arbitrary space-like photon momenta, and a Gegenbauer expansion was used to confirm that about 98% of the π⁰-pole contribution was determined in a model-independent way. The analysis also included finite-volume corrections and chiral and continuum extrapolations and yielded a value for the π⁰ decay width.

The development of a more accurate and model-independent anomalous magnetic moment for the muon has reduced major theoretical uncertainties and can make Standard Model precision tests more robust.

Read the full article

Lattice QCD calculation of the π0-pole contribution to the hadronic light-by-light scattering in the anomalous magnetic moment of the muon

Tian Lin et al 2025 Rep. Prog. Phys. 88 080501

Do you want to learn more about this topic?

The muon Smasher’s guide Hind Al Ali et al (2022)

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How does quantum entanglement move between different particles?

Paul Mabey — Wed, 17 Dec 2025 08:16:11 +0000

Entanglement is a phenomenon where two or more particles become linked in such a way that a measurement on one of the particles instantly influences the state of the other, no matter how far apart they are. It is a defining property of quantum mechanics, which is key to all quantum technologies and remains a serious challenge to realize in large systems.

However, a team of researchers from Sweden and Spain has recently made a large step forward in the field of ultrafast entanglement. Here, pairs of extreme ultraviolet pulses are used to exert quantum control on the attosecond timescale (a few quintillionths of a second).

Specifically, they studied ultrafast photoionisation. In this process, a high-energy light pulse hits an atom, ejecting an electron and leaving behind an ion.

This process can create entanglement between the electron and the ion in a controlled way. However, the entanglement is fragile and can be disrupted or transferred as the system evolves.

For instance, as the newly-created ion emits a photon to release energy, the entanglement shifts from the electron – ion pair to the electron–photon pair. This transfer process takes a considerable amount of time, on the scale of 10s of nanoseconds. This means that the ion-electron pair is macroscopically separated, on the centimetre scale.

The team found that during this transition, all three particles – electron, ion, and photon – are entangled together in a multipartite state.

They did this by using a mathematical tool called von Neumann entropy to track how much information is shared between all three particles.

Although this work was purely theoretical, they also proposed an experimental method to study entanglement transfer. The setup would use two synchronised free-electron laser pulses, with attosecond precision, to measure the electron’s energy and to detect if a photon was emitted. By measuring both particles in coincidence, entanglement can be detected.

The results could be generalised to other scenarios and will help us understand how quantum information can move between different particles. This brings us one small step closer to future technologies like quantum communication and computing.

Read the full article

Entanglement transfer in a composite electron–ion–photon system – IOPscience

A. Stenquist et al 2025 Rep. Prog. Phys. 88 080502

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Motion through quantum space–time is traced by ‘q-desics’

No Author — Tue, 16 Dec 2025 16:19:23 +0000

Physicists searching for signs of quantum gravity have long faced a frustrating problem. Even if gravity does have a quantum nature, its effects are expected to show up only at extremely small distances, far beyond the reach of experiments. A new theoretical study by Benjamin Koch and colleagues at the Technical University of Vienna in Austria suggests a different strategy. Instead of looking for quantum gravity where space–time is tiny, the researchers argue that subtle quantum effects could influence how particles and light move across huge cosmical distances.

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Their work introduces a new concept called q-desics, short for quantum-corrected paths through space–time. These paths generalize the familiar trajectories predicted by Einstein’s general theory of relativity and could, in principle, leave observable fingerprints in cosmology and astrophysics.

General relativity and quantum mechanics are two of the most successful theories in physics, yet they describe nature in radically different ways. General relativity treats gravity as the smooth curvature of space–time, while quantum mechanics governs the probabilistic behavior of particles and fields. Reconciling the two has been one of the central challenges of theoretical physics for decades.

“One side of the problem is that one has to come up with a mathematical framework that unifies quantum mechanics and general relativity in a single consistent theory,” Koch explains. “Over many decades, numerous attempts have been made by some of the most brilliant minds humanity has to offer.” Despite this effort, no approach has yet gained universal acceptance.

Deeper difficulty

There is another, perhaps deeper difficulty. “We have little to no guidance, neither from experiments nor from observations that could tell us whether we actually are heading in the right direction or not,” Koch says. Without experimental clues, many ideas about quantum gravity remain largely speculative.

That does not mean the quest lacks value. Fundamental research often pays off in unexpected ways. “We rarely know what to expect behind the next tree in the jungle of knowledge,” Koch says. “We only can look back and realize that some of the previously explored trees provided treasures of great use and others just helped us to understand things a little better.”

Almost every test of general relativity relies on a simple assumption. Light rays and freely falling particles follow specific paths, known as geodesics, determined entirely by the geometry of space–time. From gravitational lensing to planetary motion, this idea underpins how physicists interpret astronomical data.

Koch and his collaborators asked what happens to this assumption when space–time itself is treated as a quantum object. “Almost all interpretations of observational astrophysical and astronomical data rest on the assumption that in empty space light and particles travel on a path which is described by the geodesic equation,” Koch says. “We have shown that in the context of quantum gravity this equation has to be generalized.”

Generalized q-desic

The result is the q-desic equation. Instead of relying only on an averaged, classical picture of space–time, q-desics account for the underlying quantum structure more directly. In practical terms, this means that particles may follow paths that deviate slightly from those predicted by classical general relativity, even when space–time looks smooth on average.

Crucially, the team found that these deviations are not confined to tiny distances. “What makes our first results on the q-desics so interesting is that apart from these short distance effects, there are also long range effects possible, if one takes into account the existence of the cosmological constant,” Koch says.

This opens the door to possible tests using existing astronomical data. According to the study, q-desics could differ from ordinary geodesics over cosmological distances, affecting how matter and light propagate across the universe.

“The q-desics might be distinguished from geodesics at cosmological large distances,” Koch says, “which would be an observable manifestation of quantum gravity effects.”

Cosmological tensions

The researchers propose revisiting cosmological observations. “Currently, there are many tensions popping up between the Standard Model of cosmology and observed data,” Koch notes. “All these tensions are linked, one way or another, to the use of geodesics at vastly different distance scales.” The q-desic framework offers a new lens through which to examine such discrepancies.

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So far, the team has explored simplified scenarios and idealized models of quantum space–time. Extending the framework to more realistic situations will require substantial effort.

“The initial work was done with one PhD student (Ali Riahina) and one colleague (Ángel Rincón),” Koch says. “There are many things to be revisited and explored that our to-do list is growing far too long for just a few people.” One immediate goal is to encourage other researchers to engage with the idea and test it in different theoretical settings.

Whether q-desics will provide an observational window into quantum gravity remains to be seen. But by shifting attention from the smallest scales to the largest structures in the cosmos, the work offers a fresh perspective on an enduring problem.

The research is described in Physical Review D.

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From building a workforce to boosting research and education – future quantum leaders have their say

Matin Durrani — Tue, 16 Dec 2025 11:15:08 +0000

The International Year of Quantum Science and Technology has celebrated all the great developments in the sector – but what challenges and opportunities lie in store? That was the question deliberated by four future leaders in the field at the Royal Institution in central London in November. The discussion took place during the two-day conference “Quantum science and technology: the first 100 years; our quantum future”, which was part of a week-long series of quantum-related events in the UK organized by the Institute of Physics.

As well as outlining the technical challenges in their fields, the speakers all stressed the importance of developing a “skills pipeline” so that the quantum sector has enough talented people to meet its needs. Also vital will be the need to communicate the mysteries and potential of quantum technology – not just to the public but to industrialists, government officials and venture capitalists.

Two of the speakers – Nicole Gillett (Riverlane) and Muhammad Hamza Waseem (Quantinuum) – are from the quantum tech industry, with Mehul Malik (Heriot-Watt University) and Sarah Alam Malik (University College London) based in academia. The following is an edited version of the discussion.

Quantum’s future leaders

Deep thinkers The challenges and opportunities for quantum science and technology were discussed during a conference organized by the Institute of Physics at the Royal Institution on 5 November 2025 by (left to right, seated) Muhammad Hamza Waseem; Sarah Alam Malik; Mehul Malik; and Nicole Gillett. The discussion was chaired by Physics World editor-in-chief Matin Durrani (standing, far right). (Courtesy: Tushna Commissariat)

Nicole Gillett is a senior software engineer at Riverlane, in Cambridge, UK. The company is a leader in quantum error correction, which is a critical part of a fully functioning, fault-tolerant quantum computer. Errors arise because quantum bits, or qubits, are so fragile and correcting them is far trickier than with classical devices. Riverlane is therefore trying to find ways to correct for errors without disturbing a device’s quantum states. Gillett is part of a team trying to understand how best to implement error-correcting algorithms on real quantum-computing chips.

Mehul Malik, who studied physics at a liberal arts college in New York, was attracted to quantum physics because of what he calls a “weird middle ground between artistic creative thought and the rigour of physics”. After doing a PhD at the University of Rochester, he spent five years as a postdoc with Anton Zeilinger at the University of Vienna in Austria before moving to Heriot-Watt University in the UK. As head of its Beyond Binary Quantum Information research group, Malik works on quantum information processing and communication and fundamental studies of entanglement.

Sarah Alam Malik is a particle physicist at University College London, using particle colliders to detect and study potential candidates for dark matter. She is also trying to use quantum computers to speed up the discovery of new physics given that what she calls “our most cherished and compelling theories” for physics beyond the Standard Model, such as supersymmetry, have not yet been seen. In particular, Malik is trying to find new physics in a way that’s “model agnostic” – in other words, using quantum computers to search particle-collision data for anomalous events that have not been seen before.

Muhammad Hamza Waseem studied electrical engineering in Pakistan, but got hooked on quantum physics after getting involved in recreating experiments to test Bell’s inequalities in what he claims was the first quantum optics lab in the country. Waseem then moved to the the University of Oxford in the UK, to do a PhD studying spin waves to make classical and quantum logic circuits. Unable to work when his lab shut during the COVID-19 pandemic, Waseem approached Quantinuum to see if he could help them in their quest to build quantum computers using ion traps. Now based at the company, he studies how quantum computers can do natural-language processing. “Think ChatGPT, but powered with quantum computers,” he says.

What will be the biggest or most important application of quantum technology in your field over the next 10 years?

Nicole Gillett: If you look at roadmaps of quantum-computing companies, you’ll find that IBM, for example, intends to build the world’s first utility scale and fault-tolerant quantum computer by the end of the decade. Beyond 2033, they’re committing to have a system that could support 2000 “logical qubits”, which are essentially error-corrected qubits, in which the data of one qubit has been encoded into many qubits.

What can be achieved with that number of qubits is a difficult question to answer but some theorists, such as Juan Maldacena, have proposed some very exotic ideas, such as using a system of 7000 qubits to simulate black-hole dynamics. Now that might not be a particularly useful industry application, but it tells you about the potential power of a machine like this.

Mehul Malik: In my field, quantum networks that can distribute individual quantum particles or entangled states over large and short distances will have a significant impact within the next 10 years. Quantum networks will connect smaller, powerful quantum processors to make a larger quantum device, whether for computing or communication. The technology is quite mature – in fact, we’ve already got a quantum network connecting banks in London.

I will also add something slightly controversial. We often try to distinguish between quantum and non-quantum technologies, but what we’re heading towards is combining classical state-of-the-art devices with technology based on inherently quantum effects – what you might call “quantum adjacent technology”. Single-photon detectors, for example, are going to revolutionize healthcare, medical imaging and even long-distance communication.

Sarah Alam Malik: For me, the biggest impact of quantum technology will be applying quantum computing algorithms in physics. Can we quantum simulate the dynamics of, say, proton–proton collisions in a more efficient and accurate manner? Can we combine quantum computing with machine learning to sift through data and identify anomalous collisions that are beyond those expected from the Standard Model?

Quantum technology is letting us ask very fundamental questions about nature.
+Sarah Alam Malik, University College London

Quantum technology, in other words, is letting us ask very fundamental questions about nature. Emerging in theoretical physics, for example, is the idea that the fundamental layer of reality may not be particles and fields, but units of quantum information. We’re looking at the world through this new quantum-theoretic lens and asking questions like, whether it’s possible to measure entanglement in top quarks and even explore Bell-type inequalities at particle colliders.

One interesting quantity is “magic”, which is a measure of how far you are from having something that can be classically simulable (Phys. Rev. D 110 116016). The more magic there is in a system the less easy it is to simulate classically – and therefore the greater the computational resource it possesses for quantum computing. We’re asking how much “magic” there is in, for instance, top quarks produced at the Large Hadron Collider. So one of the most important developments for me may well be asking questions in a very different way to before.

Muhammad Hamza Waseem: Technologically speaking, the biggest impact will be simulating quantum systems using a quantum computer. In fact, researchers from Google already claim to have simulated a wormhole in a quantum computer, albeit a very simple version that could have been tackled with a classical device (Nature 612 55).

But the most significant impact has to do with education. I believe quantum theory teaches us that reality is not about particles and individuals – but relations. I’m not saying that particles don’t exist but they emerge from the relations. In fact, with colleagues at the University of Oxford, we’ve used this idea to develop a new way of teaching quantum theory, called Quantum in Pictures.

We’ve already tried our diagrammatic approach with a group of 16–18-year-olds, teaching them the entire quantum-information course that’s normally given to postgraduates at Oxford. At the end of our two-month course, which had one lecture and tutorial per week, students took an exam with questions from past Oxford papers. An amazing 80% of students passed and half got distinctions.

For quantum theory to have a big impact, we have to make quantum physics more accessible to everyone.
+Muhammad Hamza Waseem, Quantinuum

I’ve also tried the same approach on pupils in Pakistan: the youngest, who was just 13, can now explain quantum teleportation and quantum entanglement. My point is that for quantum theory to have a big impact, we have to make quantum physics more accessible to everyone.

What will be the biggest challenges and difficulties over the next 10 years for people in quantum science and technology?

Nicole Gillett: The challenge will be building up a big enough quantum workforce. Sometimes people hear the words “quantum computer” and get scared, worrying they’re going to have to solve Hamiltonians all the time. But is it possible to teach students at high-school level about these concepts? Can we get the ideas across in a way that is easy to understand so people are interested and excited about quantum computing?

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At Riverlane, we’ve run week-long summer workshops for the last two years, where we try to teach undergraduate students enough about quantum error correction so they can do “decoding”. That’s when you take the results of error correction and try to figure out what errors occurred on your qubits. By combining lectures and hands-on tutorials we found we could teach students about error corrections – and get them really excited too.

Our biggest challenge will be not having a workforce ready for quantum computing.
+Nicole Gillett, Riverlane

We had students from physics, philosophy, maths and computer science take the course – the only pre-requisite, apart from being curious about quantum computers, is some kind of coding ability. My point is that these kinds of boot camps are going to be so important to inspire future generations. We need to make the information accessible to people because otherwise our biggest challenge will be not having a workforce ready for quantum computing.

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Mehul Malik: One of the big challenges is international cooperation and collaboration. Imagine if, in the early days of the Internet, the US military had decided they’d keep it to themselves for national-security reasons or if CERN hadn’t made the World Wide Web open source. We face the same challenge today because we live in a world that’s becoming polarized and protectionist – and we don’t want that to hamper international collaboration.

Over the last few decades, quantum science has developed in a very international way and we have come so far because of that. I have lived in four different continents, but when I try to recruit internationally, I face significant hurdles from the UK government, from visa fees and so on. To really progress in quantum tech, we need to collaborate and develop science in a way that’s best for humanity not just for each nation.

Sarah Alam Malik: One of the most important challenges will be managing the hype that inevitably surrounds the field right now. We’ve already seen this with artificial intelligence (AI), which has gone though the whole hype cycle. Lots of people were initially interested, then the funding dried up when reality didn’t match expectations. But now AI has come back with such resounding force that we’re almost unprepared for all the implications of it.

Quantum can learn from the AI hype cycle, finding ways to manage expectations of what could be a very transformative technology. In the near- and mid-term, we need to not overplay things and be cautious of this potentially transformative technology – yet be braced for the impact it could potentially have. It’s a case of balancing hype with reality.

Muhammad Hamza Waseem: Another important challenge is how to distribute funding between research on applications and research on foundations. A lot of the good technology we use today emerged from foundational ideas in ways that were not foreseen by the people originally working on them. So we must ensure that foundational research gets the funding it deserves or we’ll hit a dead end at some point.

Will quantum tech alter how we do research, just as AI could do?

Mehul Malik: AI is already changing how I do research, speeding up the way I discover knowledge. Using Google Gemini, for example, I now ask my browser questions instead of searching for specific things. But you still have to verify all the information you gather, for example, by checking the links it cites. I recently asked AI a complex physics question to which I knew the answer and the solution it gave was terrible. As for how quantum is changing research, I’m less sure, but better detectors through quantum-enabled research will certainly be good.

Muhammad Hamza Waseem: AI is already being deployed in foundational research, for example, to discover materials for more efficient batteries. A lot of these applications could be integrated with quantum computing in some way to speed work up. In other words, a better understanding of quantum tech will let us develop AI that is safer, more reliable, more interpretable – and if something goes wrong, you know how to fix it. It’s an exciting time to be a researcher, especially in physics.

Sarah Alam Malik: I’ve often wondered if AI, with the breadth of knowledge that it has across all different fields, already has answers to questions that we couldn’t answer – or haven’t been able to answer – just because of the boundaries between disciplines. I’m a physicist and so can’t easily solve problems in biology. But could AI help us to do breakthrough research at the interface between disciplines?

What lessons can we learn from the boom in AI when it comes to the long-term future of quantum tech?

Nicole Gillett: As a software engineer, I once worked at an Internet security company called CloudFlare, which taught me that it’s never too early to be thinking about how any new technology – both AI and quantum – might be abused. What’s also really interesting is whether AI and machine learning can be used to build quantum computers by developing the coding algorithms they need. Companies like Google are active in this area and so are Riverlane too.

Mehul Malik: I recently discussed this question with a friend who works in AI, who said that the huge AI boom in industry, with all the money flowing in to it, has effectively killed academic research in the field. A lot of AI research is now industry-led and goal-orientated – and there’s a risk that the economic advantages of AI will kill curiosity-driven research. The remedy, according to my friend, is to pay academics in AI more as they are currently being offered much larger salaries to work in the private sector.

We need to diversify so that the power to control or chart the course of quantum technologies is not in the hands of a few privileged monopolies.
+Mehul Malik, Heriot-Watt University

Another issue is that a lot of power is in the hands a just a few companies, such as Nvidia and ASML. The lesson for the quantum sector is that we need to diversify early on so that the power to control or chart the course of quantum technologies is not in the hands of a few privileged monopolies.

Sarah Alam Malik: Quantum technology has a lot to learn from AI, which has shown that we need to break down the barriers between disciplines. After all, some of the most interesting and impactful research in AI has happened because companies can hire whoever they need to work on a particular problem, whether it’s a computer scientist, a biologist, a chemist, a physicist or a mathematician.

Nature doesn’t differentiate between biology and physics. In academia we not only need people who are hyper specialized but also a crop of generalists who are knee-deep in one field but have experience in other areas too.

The lesson from the AI boom is to blur the artificial boundaries between disciplines and make them more porous. In fact, quantum is a fantastic playground for that because it is inherently interdisciplinary. You have to bring together people from different disciplines to deliver this kind of technology.

Muhammad Hamza Waseem: AI research is in a weird situation where there are lots of excellent applications but so little is understood about how AI machines work. We have no good scientific theory of intelligence or of consciousness. We need to make sure that quantum computing research does not become like that and that academic research scientists are well-funded and not distracted by all the hype that industry always creates.

At the start of the previous century, the mathematician David Hilbert said something like “physics is becoming too difficult for the physicists”. I think quantum computing is also somewhat becoming too challenging for the quantum physicists. We need everyone to get involved for the field to reach its true potential.

Towards “green” quantum technology

(Courtesy: iStock/Peach)

Today’s AI systems use vast amounts of energy, but should we also be concerned about the environmental impact of quantum computers? Google, for example, has already carried out quantum error-correction experiments in which data from the company’s quantum computers had to be processed once every microsecond per round of error correction (Nature 638 920). “Finding ways to process it to keep up with the rate at which it’s being generated is a very interesting area of research,” says Nicole Gillett.

However, quantum computers could cut our energy consumption by allowing calculations to be performed far more quickly and efficiently than is possible with classical machines. For Mehul Malik, another important step towards “green” quantum technology will be to lower the energy that quantum devices require and to build detectors that work at room temperature and are robust against noise. Quantum computers themselves can also help, he thinks, by discovering energy-efficient technologies, materials and batteries.

A quantum laptop?

(Courtesy: iStock/inkoly)

Will we ever see portable quantum computers or will they always be like today’s cloud-computing devices in distant data centres? Muhammad Hamza Waseem certainly does not envisage a word processor that uses a quantum computer. But he points to companies like SPINQ, which has built a two quantum bit computer for educational purposes. “In a sense, we already have a portable quantum computer,” he says. For Mehul Malik, though, it’s all about the market. “If there’s a need for it,” he joked, “then somebody will make it.”

If I were science minister…

(Courtesy: Shutterstock/jenny on the moon)

When asked by Peter Knight – one of the driving forces behind the UK’s quantum-technology programme – what the panel would do if they were science minister, Nicole Gillett said she would seek to make the UK the leader in quantum computing by investing heavily in education. Mehul Malik would cut the costs of scientists moving across borders, pointing out that many big firms have been founded by immigrants. Sarah Alam Malik called for long-term funding – and not to give up if short-term gains don’t transpire. Muhammad Hamza Waseem, meanwhile, said we should invest more in education, research and the international mobility of scientists.

Stayed tuned to Physics World and our international partners throughout the year for more coverage of the IYQ.

Find out more on our quantum channel.

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Will this volcano explode, or just ooze? A new mechanism could hold some answers

Isabelle Dumé — Mon, 15 Dec 2025 16:00:53 +0000

Bubbling up: A schematic representation of a volcanic system and a snapshot of one of the team’s experiments. The shear-induced bubbles are marked with red ellipses. (Courtesy: O Roche)

An international team of researchers has discovered a new mechanism that can trigger the formation of bubbles in magma – a major driver of volcanic eruptions. The finding could improve our understanding of volcanic hazards by improving models of magma flow through conduits beneath Earth’s surface.

Volcanic eruptions are thought to occur when magma deep within the Earth’s crust decompresses. This decompression allows volatile chemicals dissolved in the magma to escape in gaseous form, producing bubbles. The more bubbles there are in the viscous magma, the faster it will rise, until eventually it tears itself apart.

“This process can be likened to a bottle of sparkling water containing dissolved volatiles that exolve when the bottle is opened and the pressure is released,” explains Olivier Roche, a member of the volcanology team at the Magmas and Volcanoes Laboratory (LMV) at the Université Clermont Auvergne (UCA) in France and lead author of the study.

Magma shearing forces could induce bubble nucleation

The new work, however, suggests that this explanation is incomplete. In their study, Roche and colleagues at UCA, the French National Research Institute for Sustainable Development (IRD), Brown University in the US and ETH Zurich in Switzerland began with the assumption that the mechanical energy in magma comes from the pressure gradient between the nucleus of a gas bubble and the ambient liquid. “However, mechanical energy may also be provided by shear stress in the magma when it is in motion,” Roche notes. “We therefore hypothesized that magma shearing forces could induce bubble nucleation too.”

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To test their theory, the researchers reproduced the internal movements of magma in liquid polyethylene oxide saturated with carbon dioxide at 80°C. They then set up a device to observe bubble nucleation in situ while the material was experiencing shear stress. They found that the energy provided by viscous shear is large enough to trigger bubble formation – even if decompression isn’t present.

The effect, which the team calls shear-induced bubble nucleation, depends on the magma’s viscosity and on the amount of gas it contains. According to Roche, the presence of this effect could help researchers determine whether an eruption is likely to be explosive or effusive. “Understanding which mechanism is at play is fundamental for hazard assessment,” he says. “If many gas bubbles grow deep in the volcano conduit in a volatile-rich magma, for example, they can combine with each other and form larger bubbles that then open up degassing conduits connected to the surface.

“This process will lead to effusive eruptions, which is counterintuitive (but supported by some earlier observations),” he tells Physics World. “It calls for the development of new conduit flow models to predict eruptive style for given initial conditions (essentially volatile content) in the magma chamber.”

Enhanced predictive power

By integrating this mechanism into future predictive models, the researchers aim to develop tools that anticipate the intensity of eruptions better, allowing scientists and local authorities to improve the way they manage volcanic hazards.

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Looking ahead, they are planning new shear experiments on liquids that contain solid particles, mimicking crystals that form in magma and are believed to facilitate bubble nucleation. In the longer term, they plan to study combinations of shear and compression, though Roche acknowledges that this “will be challenging technically”.

They report their present work in Science.

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Remote work expands collaboration networks but reduces research impact, study suggests

No Author — Mon, 15 Dec 2025 12:41:01 +0000

Academics who switch to hybrid working and remote collaboration do less impactful research. That’s according to an analysis of how scientists’ collaboration networks and academic outputs evolved before, during and after the COVID-19 pandemic (arXiv: 2511.18481). It involved studying author data from the arXiv preprint repository and the online bibliographic catalogue OpenAlex.

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To explore the geographic spread of collaboration networks, Sara Venturini from the Massachusetts Institute of Technology and colleagues looked at the average distance between the institutions of co-authors. They found that while the average distance between team members on publications increased from 2000 to 2021, there was a particularly sharp rise after 2022.

This pattern, the researchers claim, suggests that the pandemic led to scientists collaborating more often with geographically distant colleagues. They found consistent patterns when they separated papers related to COVID-19 from those in unrelated areas, suggesting the trend was not solely driven by research on COVID-19.

The researchers also examined how the number of citations a paper received within a year of publication changed with distance between the co-authors’ institutions. In general, as the average distance between collaborators increases, citations fall, the authors found.

They suggest that remote and hybrid working hampers research quality by reducing spontaneous, serendipitous in-person interactions that can lead to deep discussions and idea exchange.

Despite what the authors say is a “concerning decline” in citation impact, there are, however, benefits to increasing remote interactions. In particular, as the geography of collaboration networks increases, so too does international partnerships and authorship diversity.

Remote tools

Lingfei Wu, a computational social scientist at the University of Pittsburgh, who was not involved in the study, told Physics World that he was surprised by the finding that remote teams produce less impactful work.

“In our earlier research, we found that historically, remote collaborations tended to produce more impactful but less innovative work,” notes Wu. “For example, the Human Genome Project published in 2001 shows how large, geographically distributed teams can also deliver highly impactful science. One would expect the pandemic-era shift toward remote collaboration to increase impact rather than diminish it.”

Wu says his work suggests that remote work is effective for implementing ideas but less effective for generating them, indicating that scientists need a balance between remote and in-person interactions. “Use remote tools for efficient execution, but reserve in-person time for discussion, brainstorming, and informal exchange,” he adds.

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How well do you know AI? Try our interactive quiz to find out

No Author — Mon, 15 Dec 2025 12:00:02 +0000

There are 12 questions in total: blue is your current question and white means unanswered, with green and red being right and wrong. Check your scores at the end – and why not test your colleagues too?

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How did you do?

10–12 Top shot – congratulations, you’re the next John Hopfield

7–9 Strong skills – good, but not quite Nobel standard

4–6 Weak performance – should have asked ChatGPT

0–3 Worse than random – are you a bot?

Physics World‘s coverage of this interactive quiz is supported by Reports on Progress in Physics, which offers unparalleled visibility for your ground-breaking research.

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International Year of Quantum Science and Technology quiz

Matin Durrani — Mon, 15 Dec 2025 10:00:08 +0000

This quiz was first published in February 2025. Now you can enjoy it in our new interactive quiz format and check your final score. There are 18 questions in total: blue is your current question and white means unanswered, with green and red being right and wrong.

+ + +

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Components of RNA among life’s building blocks found in NASA asteroid sample

Fri, 12 Dec 2025 11:30:01 +0000

Institute of Physics celebrates 2025 Business Award winners at parliamentary event

Some 14 firms have won IOP business awards in 2025, bringing total tally to 102

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Leftover gamma rays produce medically important radioisotopes

Top 10 Breakthroughs of the Year in physics for 2025 revealed

Physics World is delighted to announce its Top 10 Breakthroughs of the Year for 2025, which includes research in astronomy, antimatter, atomic and molecular physics and more. The Top Ten is the shortlist for the Physics World Breakthrough of the Year, which will be revealed on Thursday 18 December.

+ Physics World is delighted to announce its Top 10 Breakthroughs of the Year for 2025, which includes research in astronomy, antimatter, atomic and molecular physics and more. The Top Ten is the shortlist for the Physics World Breakthrough of the Year, which will be revealed on Thursday 18 December.

Our editorial team has looked back at all the scientific discoveries we have reported on since 1 January and has picked 10 that we think are the most important. In addition to being reported in Physics World in 2025, the breakthroughs must meet the following criteria:

Significant advance in knowledge or understanding

Here, then, are the Physics World Top 10 Breakthroughs for 2025, listed in no particular order. You can listen to Physics World editors make the case for each of our nominees in the Physics World Weekly podcast. And, come back next week to discover who has bagged the 2025 Breakthrough of the Year.

Finding the stuff of life on an asteroid

To Tim McCoy, Danny Glavin, Jason Dworkin, Yoshihiro Furukawa, Ann Nguyen, Scott Sandford, Zack Gainsforth and an international team of collaborators for identifying salt, ammonia, sugar, nitrogen- and oxygen-rich organic materials, and traces of metal-rich supernova dust, in samples returned from the near-Earth asteroid 101955 Bennu. The incredible chemical richness of this asteroid, which NASA’s OSIRIS-REx spacecraft visited in 2020, lends support to the longstanding hypothesis that asteroid impacts could have “seeded” the early Earth with the raw ingredients needed for life to form. The discoveries also enhance our understanding of how Bennu and other objects in the solar system formed out of the disc of material that coalesced around the young Sun.

The first superfluid molecule

Hollow-core fibres break 40-year limit on light transmission

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Jesper Grimstrup’s The Ant Mill: could his anti-string-theory rant do string theorists a favour?

Robert P Crease — Wed, 15 Oct 2025 10:00:42 +0000

Imagine you had a bad breakup in college. Your ex-partner is furious and self-publishes a book that names you in its title. You’re so humiliated that you only dimly remember this ex, though the book’s details and anecdotes ring true.

According to the book, you used to be inventive, perceptive and dashing. Then you started hanging out with the wrong crowd, and became competitive, self-involved and incapable of true friendship. Your ex struggles to turn you around; failing, they leave. The book, though, is so over-the-top that by the end you stop cringing and find it a hoot.

That’s how I think most Physics World readers will react to The Ant Mill: How Theoretical High-energy Physics Descended into Groupthink, Tribalism and Mass Production of Research. Its author and self-publisher is the Danish mathematician-physicist Jesper Grimstrup, whose previous book was Shell Beach: the Search for the Final Theory.

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After receiving his PhD in theoretical physics at the Technical University of Vienna in 2002, Grimstrup writes, he was “one of the young rebels” embarking on “a completely unexplored area” of theoretical physics, combining elements of loop quantum gravity and noncommutative geometry. But there followed a decade of rejected articles and lack of opportunities.

Grimstrup became “disillusioned, disheartened, and indignant” and in 2012 left the field, selling his flat in Copenhagen to finance his work. Grimstrup says he is now a “self-employed researcher and writer” who lives somewhere near the Danish capital. You can support him either through Ko-fi or Paypal.

Fomenting fear

The Ant Mill opens with a copy of the first page of the letter that Grimstrup’s fellow Dane Niels Bohr sent in 1917 to the University of Copenhagen successfully requesting a four-storey building for his physics institute. Grimstrup juxtaposes this incident with the rejection of his funding request, almost a century later, by the Danish Council for Independent Research.

Today, he writes, theoretical physics faces a situation “like the one it faced at the time of Niels Bohr”, but structural and cultural factors have severely hampered it, making it impossible to pursue promising new ideas. These include Grimstrup’s own “quantum holonomy theory, which is a candidate for a fundamental theory”. The Ant Mill is his diagnosis of how this came about.

The Standard Model of particle physics, according to Grimstrup, is dominated by influential groups that squeeze out other approaches
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A major culprit, in Grimstrup’s eyes, was the Standard Model of particle physics. That completed a structure for which theorists were trained to be architects and should have led to the flourishing of a new crop of theoretical ideas. But it had the opposite effect. The field, according to Grimstrup, is now dominated by influential groups that squeeze out other approaches.

The biggest and most powerful is string theory, with loop quantum gravity its chief rival. Neither member of the coterie can make testable predictions, yet because they control jobs, publications and grants they intimidate young researchers and create what Grimstrup calls an “undercurrent of fear”. (I leave assessment of this claim to young theorists.)

Roughly half the chapters begin with an anecdote in which Grimstrup describes an instance of rejection by a colleague, editor or funding agency. In the book’s longest chapter Grimstrup talks about his various rejections – by the Carlsberg Foundation, The European Physics Journal C, International Journal of Modern Physics A, Classical and Quantum Gravity, Reports on Mathematical Physics, Journal of Geometry and Physics and the Journal of Noncommutative Geometry.

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Grimstrup says that the reviewers and editors of these journals told him that his papers variously lacked concrete physical results, were exercises in mathematics, seemed the same as other papers, or lacked “relevance and significance”. Grimstrup sees this as the coterie’s handiwork, for such journals are full of string theory papers open to the same criticism.

“Science is many things,” Grimstrup writes at the end. “[S]imultaneously boring and scary, it is both Indiana Jones and anonymous bureaucrats, and it is precisely this diversity that is missing in the modern version of science.” What the field needs is “courage…hunger…ambition…unwillingness to compromise…anarchy”.

Grimstrup hopes that his book will have an impact, helping to inspire young researchers to revolt, and to make all the scientific bureaucrats and apparatchiks and bookkeepers and accountants “wake up and remember who they truly are”.

The critical point

The Ant Mill is an example of what I have called “rant literature” or rant-lit. Evangelical, convinced that exposing truth will make sinners come to their senses and change their evil ways, rant lit can be fun to read, for it is passionate and full of florid metaphors.

Theoretical physicists, Grimstrup writes, have become “obedient idiots” and “technicians” (the phrase appearing in an e-mail cited in the book that was written by an unidentified person with whom the author disagrees). Theoretical physics, he suggests, has become a “kingdom”, a “cult”, a “hamster wheel” and “ant mill”, in which the ants march around in a pre-programmed “death spiral”.

Grimstrup hammers away at theories lacking falsifiability, but his vehemence invites you to ask: “Is falsifiability really the sole criterion for deciding whether to accept or fail to pursue a theory?”
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An attentive reader, however, may come away with a different lesson. Grimstrup calls falsifiability the “crown jewel of the natural sciences” and hammers away at theories lacking it. But his vehemence invites you to ask: “Is falsifiability really the sole criterion for deciding whether to accept or fail to pursue a theory?”

In his 2013 book String Theory and the Scientific Method, for instance, the Stockholm University philosopher of science Richard Dawid suggested rescuing the scientific status of string theory by adding such non-empirical criteria to evaluating theories as clarity, coherence and lack of alternatives. It’s an approach that both rescues the formalistic approach to the scientific method and undermines it.

Dawid, you see, is making the formalism follow the practice rather than the other way around. In other words, he is able to reformulate how we make theories because he already knows how theorizing works – not because he only truly knows what it is to theorize after he gets the formalism right.

Grimstrup’s rant, too, might remind you of the birth of the Yang–Mills theory in 1954. Developed by Chen Ning Yang and Robert Mills, it was a theory of nuclear binding that integrated much of what was known about elementary particle theory but implied the existence of massless force-carrying particles that then were known not to exist. In fact, at one seminar Wolfgang Pauli unleashed a tirade against Yang for proposing so obviously flawed a theory.

The theory, however, became central to theoretical physics two decades later, after theorists learned more about the structure of the world. The Yang–Mills story, in other words, reveals that theory-making does not always conform to formal strictures and does not always require a testable prediction. Sometimes it just articulates the best way to make sense of the world apart from proof or evidence.

The lesson I draw is that becoming the target of a rant might not always make you feel repentant and ashamed. It might inspire you into deep reflection on who you are in a way that is insightful and vindicating. It might even make you more rather than less confident about why you’re doing what you’re doing

Your ex, of course, would be horrified.

Jesper Grimstrup published an entry on his blog, dated 1 November 2025, expressing his views on this review.

The post Jesper Grimstrup’s The Ant Mill: could his anti-string-theory rant do string theorists a favour? appeared first on Physics World.

Further evidence for evolving dark energy?

Paul Mabey — Wed, 15 Oct 2025 09:34:58 +0000

The term dark energy, first used in 1998, is a proposed form of energy that affects the universe on the largest scales. Its primary effect is to drive the accelerating expansion of the universe – an observation that was awarded the 2011 Nobel Prize in Physics.

Dark energy is now a well established concept and forms a key part of the standard model of Big Bang cosmology, the Lambda-CDM model.

The trouble is, we’ve never really been able to explain exactly what dark energy is, or why it has the value that it does.

Even worse, new data acquired by cutting-edge telescopes have suggested that dark energy might not even exist as we had imagined it.

This is where the new work by Mukherjee and Sen comes in. They combined two of these datasets, while making as few assumptions as possible, to understand what’s going on.

The first of these datasets came from baryon acoustic oscillations. These are patterns in the distribution of matter in the universe, created by sound waves in the early universe.

The second dataset is based on a survey of supernovae data from the last 5 years. Both sets of data can be used to track the expansion history of the universe by measuring distances at different snapshots in time.

The team’s results are in tension with the Lambda-CDM model at low redshifts. Put simply, the results disagree with the current model at recent times. This provides further evidence for the idea that dark energy, previously considered to have a constant value, is evolving over time.

The tension in the expansion rate is most evident at low redshifts (Courtesy: P. Mukherjee)

The is far from the end of the story with dark energy. New observational data, and new analyses such as this one are urgently required to provide a clearer picture.

However, where there’s uncertainty, there’s opportunity. Understanding dark energy could hold the key to understanding quantum gravity, the Big Bang and the ultimate fate of the universe.

Read the full article

New expansion rate anomalies at characteristic redshifts geometrically determined using DESI-DR2 BAO and DES-SN5YR observations – IOPscience

Mukherjee and Sen, 2025 Rep. Prog. Phys. 88 098401

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Searching for dark matter particles

Paul Mabey — Wed, 15 Oct 2025 09:34:56 +0000

Dark matter is hypothesised form of matter that does not emit, absorb, or reflect light, making it invisible to electromagnetic observations. Although we have never detected it, its existence is inferred from its gravitational effects on visible matter and the large-scale structure of the universe.

The Standard Model of particle physics does not contain any dark matter particles but there have been several proposed extensions of how they might be included. Several of these are very low mass particles such as the axion or the sterile neutrino.

Detecting these hypothesised particles is very challenging, however, due to the extreme sensitivity required.

Electromagnetic resonant systems, such as cavities and LC circuits, are widely used for this purpose, as well as to detect high-frequency gravitational waves.

When an external signal matches one of these systems’ resonant frequencies, the system responds with a large amplitude, making the signal possible to detect. However, there is always a trade-off between the sensitivity of the detector and the range of frequencies it is able to detect (its bandwidth).

A natural way to overcome this compromise is to consider multi-mode resonators, which can be viewed as coupled networks of harmonic oscillators. Their scan efficiency can be significantly enhanced beyond the standard quantum limit of simple single-mode resonators.

In a recent paper, the researchers demonstrated how multi-mode resonators can achieve the advantages of both sensitive and broadband detection. By connecting adjacent modes inside the resonant cavity, and tuning these interactions to comparable magnitudes, off-resonant (i.e. unwanted) frequency shifts are effectively cancelled increasing the overall response of the system.

Their method allows us to search for these elusive dark matter particles in a faster, more efficient way.

A multi-mode detector design, where the first mode couples to dark matter and the last mode is read out (Courtesy: Y. Chen)

Read the full article

Simultaneous resonant and broadband detection of ultralight dark matter and high-frequency gravitational waves via cavities and circuits – IOPscience

Chen et al. 2025 Rep. Prog. Phys. 88 057601

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Physicists explain why some fast-moving droplets stick to hydrophobic surfaces

Isabelle Dumé — Wed, 15 Oct 2025 08:00:04 +0000

What happens when a microscopic drop of water lands on a water-repelling surface? The answer is important for many everyday situations, including pesticides being sprayed on crops and the spread of disease-causing aerosols. Naively, one might expect it to depend on the droplet’s speed, with faster-moving droplets bouncing off the surface and slower ones sticking to it. However, according to new experiments, theoretical work and simulations by researchers in the UK and the Netherlands, it’s more complicated than that.

“If the droplet moves too slowly, it sticks,” explains Jamie McLauchlan, a PhD student at the University of Bath, UK who led the new research effort with Bath’s Adam Squires and Anton Souslov of the University of Cambridge. “Too fast, and it sticks again. Only in between is bouncing possible, where there is enough momentum to detach from the surface but not so much that it collapses back onto it.”

As well as this new velocity-dependent condition, the researchers also discovered a size effect in which droplets that are too small cannot bounce, no matter what their speed. This size limit, they say, is set by the droplets’ viscosity, which prevents the tiniest droplets from leaving the surface once they land on it.

Smaller-sized, faster-moving droplets

While academic researchers and industrialists have long studied single-droplet impacts, McLauchlan says that much of this earlier work focused on millimetre-sized drops that took place on millisecond timescales. “We wanted to push this knowledge to smaller sizes of micrometre droplets and faster speeds, where higher surface-to-volume ratios make interfacial effects critical,” he says. “We were motivated even further during the COVID-19 pandemic, when studying how small airborne respiratory droplets interact with surfaces became a significant concern.”

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Working at such small sizes and fast timescales is no easy task, however. To record the outcome of each droplet landing, McLauchlan and colleagues needed a high-speed camera that effectively slowed down motion by a factor of 100 000. To produce the droplets, they needed piezoelectric droplet generators capable of dispensing fluid via tiny 30-micron nozzles. “These dispensers are highly temperamental,” McLauchlan notes. “They can become blocked easily by dust and fibres and fail to work if the fluid viscosity is too high, making experiments delicate to plan and run. The generators are also easy to break and expensive.”

Droplet modelled as a tiny spring

The researchers used this experimental set-up to create and image droplets between 30‒50 µm in diameter as they struck water-repelling surfaces at speeds of 1‒10 m/s. They then compared their findings with calculations based on a simple mathematical model that treats a droplet like a tiny spring, taking into account three main parameters in addition to its speed: the stickiness of the surface; the viscosity of the droplet liquid; and the droplet’s surface tension.

Previous research had shown that on perfectly non-wetting surfaces, bouncing does not depend on velocity. Other studies showed that on very smooth surfaces, droplets can bounce on a thin air layer. “Our work has explored a broader range of hydrophobic surfaces, showing that bouncing occurs due to a delicate balance of kinetic energy, viscous dissipation and interfacial energies,” McLauchlan tells Physics World.

This is exciting, he adds, because it reveals a previously unexplored regime for bounce behaviour: droplets that are too small, or too slow, will always stick, while sufficiently fast droplets can rebound. “This finding provides a general framework that explains bouncing at the micron scale, which is directly relevant for aerosol science,” he says.

A novel framework for engineering microdroplet processes

McLauchlan thinks that by linking bouncing to droplet velocity, size and surface properties, the new framework could make it easier to engineer microdroplets for specific purposes. “In agriculture, for example, understanding how spray velocities interact with plant surfaces with different hydrophobicity could help determine when droplets deposit fully versus when they bounce away, improving the efficiency of crop spraying,” he says.

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Such a framework could also be beneficial in the study of airborne diseases, since exhaled droplets frequently bump into surfaces while floating around indoors. While droplets that stick are removed from the air, and can no longer transmit disease via that route, those that bounce are not. Quantifying these processes in typical indoor environments will provide better models of airborne pathogen concentrations and therefore disease spread, McLauchlan says. For example, in healthcare settings, coatings could be designed to inhibit or promote bouncing, ensuring that high-velocity respiratory droplets from sneezes either stick to hospital surfaces or recoil from them, depending on which mode of potential transmission (airborne or contact-based) is being targeted.

The researchers now plan to expand their work on aqueous droplets to droplets with more complex soft-matter properties. “This will include adding surfactants, which introduce time-dependent surface tensions, and polymers, which give droplets viscoelastic properties similar to those found in biological fluids,” McLauchlan reveals. “These studies will present significant experimental challenges, but we hope they broaden the relevance of our findings to an even wider range of fields.”

The present work is detailed in PNAS.

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Quantum computing on the verge: a look at the quantum marketplace of today

No Author — Tue, 14 Oct 2025 15:40:42 +0000

“I’d be amazed if quantum computing produces anything technologically useful in ten years, twenty years, even longer.” So wrote University of Oxford physicist David Deutsch – often considered the father of the theory of quantum computing – in 2004. But, as he added in a caveat, “I’ve been amazed before.”

We don’t know how amazed Deutsch, a pioneer of quantum computing, would have been had he attended a meeting at the Royal Society in London in February on “the future of quantum information”. But it was tempting to conclude from the event that quantum computing has now well and truly arrived, with working machines that harness quantum mechanics to perform computations being commercially produced and shipped to clients. Serving as the UK launch of the International Year of Quantum Science and Technology (IYQ) 2025, it brought together some of the key figures of the field to spend two days discussing quantum computing as something like a mature industry, even if one in its early days.

Werner Heisenberg – who worked out the first proper theory of quantum mechanics 100 years ago – would surely have been amazed to find that the formalism he and his peers developed to understand the fundamental behaviour of tiny particles had generated new ways of manipulating information to solve real-world problems in computation. So far, quantum computing – which exploits phenomena such as superposition and entanglement to potentially achieve greater computational power than the best classical computers can muster – hasn’t tackled any practical problems that can’t be solved classically.

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Although the fundamental quantum principles are well-established and proven to work, there remain many hurdles that quantum information technologies have to clear before this industry can routinely deliver resources with transformative capabilities. But many researchers think that moment of “practical quantum advantage” is fast approaching, and an entire industry is readying itself for that day.

Entangled marketplace

So what are the current capabilities and near-term prospects for quantum computing?

The first thing to acknowledge is that a booming quantum-computing market exists. Devices are being produced for commercial use by a number of tech firms, from the likes of IBM, Google, D-Wave, and Rigetti who have been in the field for a decade or more; to relative newcomers like Nord Quantique (Canada), IQM (Finland), Quantinuum (UK and US), Orca (UK) and PsiQuantum (US), Silicon Quantum Computing (Australia), see box below, “The global quantum ecosystem”.

The global quantum ecosystem

(Courtesy: QURECA)

We are on the cusp of a second quantum revolution, with quantum science and technologies growing rapidly across the globe. This includes quantum computers; quantum sensing (ultra-high precision clocks, sensors for medical diagnostics); as well as quantum communications (a quantum internet). Indeed, according to the State of Quantum 2024 report, a total of 33 countries around the world currently have government initiatives in quantum technology, of which more than 20 have national strategies with large-scale funding. As of this year, worldwide investments in quantum tech – by governments and industry – exceed $55.7 billion, and the market is projected to reach $106 billion by 2040. With the multitude of ground-breaking capabilities that quantum technologies bring globally, it’s unsurprising that governments all over the world are eager to invest in the industry.

With data from a number of international reports and studies, quantum education and skills firm QURECA has summarized key programmes and efforts around the world. These include total government funding spent through 2025, as well as future commitments spanning 2–10 year programmes, varying by country. These initiatives generally represent government agencies’ funding announcements, related to their countries’ advancements in quantum technologies, excluding any private investments and revenues.

A supply chain is also organically developing, which includes manufacturers of specific hardware components, such as Oxford Instruments and Quantum Machines and software developers like Riverlane, based in Cambridge, UK, and QC Ware in Palo Alto, California. Supplying the last link in this chain are a range of eager end-users, from finance companies such as J P Morgan and Goldman Sachs to pharmaceutical companies such as AstraZeneca and engineering firms like Airbus. Quantum computing is already big business, with around 400 active companies and current global investment estimated at around $2 billion.

But the immediate future of all this buzz is hard to assess. When the chief executive of computer giant Nvidia announced at the start of 2025 that “truly useful” quantum computers were still two decades away, the previously burgeoning share prices of some leading quantum-computing companies plummeted. They have since recovered somewhat, but such volatility reflects the fact that quantum computing has yet to prove its commercial worth.

The field is still new and firms need to manage expectations and avoid hype while also promoting an optimistic enough picture to keep investment flowing in. “Really amazing breakthroughs are being made,” says physicist Winfried Hensinger of the University of Sussex, “but we need to get away from the expectancy that [truly useful] quantum computers will be available tomorrow.”

The current state of play is often called the “noisy intermediate-scale quantum” (NISQ) era. That’s because the “noisy” quantum bits (qubits) in today’s devices are prone to errors for which no general and simple correction process exists. Current quantum computers can’t therefore carry out practically useful computations that could not be done on classical high-performance computing (HPC) machines. It’s not just a matter of better engineering either; the basic science is far from done.

Building up Quantum computing behemoth IBM says that by 2029, its fault-tolerant system should accurately run 100 million gates on 200 logical qubits, thereby truly achieving quantum advantage. (Courtesy: IBM)

“We are right on the cusp of scientific quantum advantage – solving certain scientific problems better than the world’s best classical methods can,” says Ashley Montanaro, a physicist at the University of Bristol who co-founded the quantum software company Phasecraft. “But we haven’t yet got to the stage of practical quantum advantage, where quantum computers solve commercially important and practically relevant problems such as discovering the next lithium-ion battery.” It’s no longer if or how, but when that will happen.

Pick your platform

As the quantum-computing business is such an emerging area, today’s devices use wildly different types of physical systems for their qubits, see the box below, “Comparing computing modalities: from qubits to architectures”

. There is still no clear sign as to which of these platforms, if any, will emerge as the winner. Indeed many researchers believe that no single qubit type will ever dominate.

The top-performing quantum computers, like those made by Google (with its 105-qubit Willow chip) and IBM (which has made the 121-qubit Condor), use qubits in which information is encoded in the wavefunction of a superconducting material. Until recently, the strongest competing platform seemed to be trapped ions, where the qubits are individual ions held in electromagnetic traps – a technology being developed into working devices by the US company IonQ, spun out from the University of Maryland, among others.

Comparing computing modalities: from qubits to architectures

(Courtesy: PatentVest)

Much like classical computers, quantum computers have a core processor and a control stack – the difference being that the core depends on the type of qubit being used. Currently, quantum computing is not based on a single platform, but rather a set of competing hardware approaches, each with its own physical basis for creating and controlling qubits and keeping them stable.

The data above – taken from the August 2025 report Quantum Computing at an Inflection Point: Who’s Leading, What They Own, and Why IP Decides Quantum’s Future by US firm Patentvest – shows the key “quantum modalities”, which refers to the different types of qubits and architectures used to build these quantum systems. Differing qubits each have their own pros and cons, with varying factors including the temperature at which they operate, coherence time, gate speed, and how easy they might be to scale up.

But over the past few years, neutral trapped atoms have emerged as a major contender, thanks to advances in controlling the positions and states of these qubits. Here the atoms are prepared in highly excited electronic states called Rydberg atoms, which can be entangled with one another over a few microns. A Harvard startup called QuEra is developing this technology, as is the French start-up Pasqal. In September a team from the California Institute of Technology announced a 6100-qubit array made from neutral atoms. “Ten years ago I would not have included [neutral-atom] methods if I were hedging bets on the future of quantum computing,” says Deutsch’s Oxford colleague, the quantum information theorist Andrew Steane. But like many, he thinks differently now.

Some researchers believe that optical quantum computing, using photons as qubits, will also be an important platform. One advantage here is that there is no need for complex conversion of photonic signals in existing telecommunications networks going to or from the processing units, which is also handy for photonic interconnections between chips. What’s more, photonic circuits can work at room temperature, whereas trapped ions and superconducting qubits need to be cooled. Photonic quantum computing is being developed by firms like PsiQuantum, Orca, and Xanadu.

Other efforts, for example at Intel and Silicon Quantum Computing in Australia, make qubits from either quantum dots (Intel) or precision-placed phosphorus atoms (SQC), both in good old silicon, which benefits from a very mature manufacturing base. “Small qubits based on ions and atoms yield the highest quality processors”, says Michelle Simmons of the University of New South Wales, who is the founder and CEO of SQC. “But only atom-based systems in silicon combine this quality with manufacturability.”

Spinning around Intel’s silicon spin qubits are now being manufactured on an industrial scale. (Courtesy: Intel Corporation)

And it’s not impossible that entirely new quantum computing platforms might yet arrive. At the start of 2025, researchers at Microsoft’s laboratories in Washington State caused a stir when they announced that they had made topological qubits from semiconducting and superconducting devices, which are less error-prone than those currently in use. The announcement left some scientists disgruntled because it was not accompanied by a peer-reviewed paper providing the evidence for these long-sought entities. But in any event, most researchers think it would take a decade or more for topological quantum computing to catch up with the platforms already out there.

Each of these quantum technologies has its own strengths and weaknesses. “My personal view is that there will not be a single architecture that ‘wins’, certainly not in the foreseeable future,” says Michael Cuthbert, founding director of the UK’s National Quantum Computing Centre (NQCC), which aims to facilitate the transition of quantum computing from basic research to an industrial concern. Cuthbert thinks the best platform will differ for different types of computation: cold neutral atoms might be good for quantum simulations of molecules, materials and exotic quantum states, say, while superconducting and trapped-ion qubits might be best for problems involving machine learning or optimization.

Measures and metrics

Given these pros and cons of different hardware platforms, one difficulty in assessing their merits is finding meaningful metrics for making comparisons. Should we be comparing error rates, coherence times (basically how long qubits remain entangled), gate speeds (how fast a single computational step can be conducted), circuit depth (how many steps a single computation can sustain), number of qubits in a processor, or what? “The metrics and measures that have been put forward so far tend to suit one or other platform more than others,” says Cuthbert, “such that it becomes almost a marketing exercise rather than a scientific benchmarking exercise as to which quantum computer is better.”

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The NQCC evaluates the performance of devices using a factor known as the “quantum operation” (QuOp). This is simply the number of quantum operations that can be carried out in a single computation, before the qubits lose their coherence and the computation dissolves into noise. “If you want to run a computation, the number of coherent operations you can run consecutively is an objective measure,” Cuthbert says. If we want to get beyond the NISQ era, he adds, “we need to progress to the point where we can do about a million coherent operations in a single computation. We’re now at the level of maybe a few thousand. So we’ve got a long way to go before we can run large-scale computations.”

One important issue is how amenable the platforms are to making larger quantum circuits. Cuthbert contrasts the issue of scaling up – putting more qubits on a chip – with “scaling out”, whereby chips of a given size are linked in modular fashion. Many researchers think it unlikely that individual quantum chips will have millions of qubits like the silicon chips of today’s machines. Rather, they will be modular arrays of relatively small chips linked at their edges by quantum interconnects.

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Having made the Condor, IBM now plans to focus on modular architectures (scaling out) – a necessity anyway, since superconducting qubits are micron-sized, so a chip with millions of them would be “bigger than your dining room table”, says Cuthbert. But superconducting qubits are not easy to scale out because microwave frequencies that control and read out the qubits have to be converted into optical frequencies for photonic interconnects. Cold atoms are easier to scale up, as the qubits are small, while photonic quantum computing is easiest to scale out because it already speaks the same language as the interconnects.

To be able to build up so called “fault tolerant” quantum computers, quantum platforms must solve the issue of error correction, which will enable more extensive computations without the results becoming degraded into mere noise.

In part two of this feature, we will explore how this is being achieved and meet the various firms developing quantum software. We will also look into the potential high-value commercial uses for robust quantum computers – once such devices exist.

This article was updated with additional content on 22 October 2025.

Stayed tuned to Physics World and our international partners throughout the year for more coverage of the IYQ.

Find out more on our quantum channel.

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Physicists achieve first entangled measurement of W states

Mira Varma — Tue, 14 Oct 2025 12:15:49 +0000

Imagine two particles so interconnected that measuring one immediately reveals information about the other, even if the particles are light–years apart. This phenomenon, known as quantum entanglement, is the foundation of a variety of technologies such as quantum cryptography and quantum computing. However, entangled states are notoriously difficult to control. Now, for the first time, a team of physicists in Japan has performed a collective quantum measurement on a W state comprising three entangled photons. This allowed them to analyse the three entangled photons at once rather than one at a time. This achievement, reported in Science Advances, marks a significant step towards the practical development of quantum technologies.

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Physicists usually measure entangled particles using a technique known as quantum tomography. In this method, many identical copies of a particle are prepared, and each copy is measured at a different angle. The results of these measurements are then combined to reconstruct its full quantum state. To visualize this, imagine being asked to take a family photo. Instead of taking one group picture, you have to photograph each family member individually and then combine all the photos into a single portrait. Now imagine taking a photo properly: taking one photograph of the entire family. This is essentially what happens in an entangled measurement: where all particles are measured simultaneously rather than separately. This approach allows for significantly faster and more efficient measurements.

So far, for three-particle systems, entangled measurements have only been performed on Greenberger–Horne–Zeilinger (GHZ) states, where all qubits (quantum bits of a system) are either in one state or another. Until now, no one had carried out an entangled measurement for a more complicated set of states known as W states, which do not share this all-or-nothing property. In their experiment, the researchers at Kyoto University and Hiroshima University specifically used the simplest type of W state, made up of three photons, where each photon’s polarization (horizontal or vertical) is represented by one qubit.

“In a GHZ state, if you measure one qubit, the whole superposition collapses. But in a W state, even if you measure one particle, entanglement still remains,” explains Shigeki Takeuchi, corresponding author of the paper describing the study. This robustness makes the W state particularly appealing for quantum technologies.

Fourier transformations

The team took advantage of the fact that different W states look almost identical but differ by tiny phase shift, which acts as a hidden label that distinguishes one state from another. Using a tool called a discrete Fourier transform (DFT) circuit, researchers were able to “decode” this phase and tell the states apart.

The DFT exploits a special type of symmetry inherent to W states. Since the method relies on symmetry, in principle it can be extended to systems containing any number of photons. The researchers prepared photons in controlled polarization states and ran them through the DFT, which provided each state’s phase label. After, the photons were sent through polarizing beam splitters that separate them into vertically and horizontally polarized groups. By counting both sets of photons, and combining this with information from the DFT, the team could identify the W state.

The experiment identified the correct W state about 87% of the time, well above the 15% success rate typically achieved using tomography-based measurements. Maintaining this level of performance was a challenge, as tiny fluctuations in optical paths or photon loss can easily destroy the fragile interference pattern. The fact that the team could maintain stable performance long enough to collect statistically reliable data marks an important technical milestone.

Scalable to larger systems

“Our device is not just a single-shot measurement: it works with 100% efficiency,” Takeuchi adds. “Most linear optical protocols are probabilistic, but here the success probability is unity.” Although demonstrated with three photons, this procedure is directly scalable to larger systems, as the key insight is the symmetry that the DFT can detect.

“In terms of applications, quantum communication seems the most promising,” says Takeuchi. “Because our device is highly efficient, our protocol could be used for robust communication between quantum computer chips. The next step is to build all of this on a tiny photonic chip, which would reduce errors and photon loss and help make this technology practical for real quantum computers and communication networks.”

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Physicists apply quantum squeezing to a nanoparticle for the first time

Isabelle Dumé — Tue, 14 Oct 2025 08:00:45 +0000

Physicists at the University of Tokyo, Japan have performed quantum mechanical squeezing on a nanoparticle for the first time. The feat, which they achieved by levitating the particle and rapidly varying the frequency at which it oscillates, could allow us to better understand how very small particles transition between classical and quantum behaviours. It could also lead to improvements in quantum sensors.

Oscillating objects that are smaller than a few microns in diameter have applications in many areas of quantum technology. These include optical clocks and superconducting devices as well as quantum sensors. Such objects are small enough to be affected by Heisenberg’s uncertainty principle, which places a limit on how precisely we can simultaneously measure the position and momentum of a quantum object. More specifically, the product of the measurement uncertainties in the position and momentum of such an object must be greater than or equal to ħ/2, where ħ is the reduced Planck constant.

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In these circumstances, the only way to decrease the uncertainty in one variable – for example, the position – is to boost the uncertainty in the other. This process has no classical equivalent and is called squeezing because reducing uncertainty along one axis of position-momentum space creates a “bulge” in the other, like squeezing a balloon.

A charge-neutral nanoparticle levitated in an optical lattice

In the new work, which is detailed in Science, a team led by Kiyotaka Aikawa studied a single, charge-neutral nanoparticle levitating in a periodic intensity pattern formed by the interference of criss-crossed laser beams. Such patterns are known as optical lattices, and they are ideal for testing the quantum mechanical behaviour of small-scale objects because they can levitate the object. This keeps it isolated from other particles and allows it to sustain its fragile quantum state.

After levitating the particle and cooling it to its motional ground state, the team rapidly varied the intensity of the lattice laser. This had the effect of changing the particle’s oscillation frequency, which in turn changed the uncertainty in its momentum. To measure this change (and prove they had demonstrated quantum squeezing), the researchers then released the nanoparticle from the trap and let it propagate for a short time before measuring its velocity. By repeating these time-of-flight measurements many times, they were able to obtain the particle’s velocity distribution.

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The telltale sign of quantum squeezing, the physicists say, is that the velocity distribution they measured for the nanoparticle was narrower than the uncertainty in velocity for the nanoparticle at its lowest energy level. Indeed, the measured velocity variance was narrower than that of the ground state by 4.9 dB, which they say is comparable to the largest mechanical quantum squeezing obtained thus far.

“Our system will enable us to realize further exotic quantum states of motions and to elucidate how quantum mechanics should behave at macroscopic scales and become classical,” Aikawa tells Physics World. “This could allow us to develop new kinds of quantum devices in the future.”

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Theoretical physicist Michael Berry wins 2025 Isaac Newton Medal and Prize

Michael Banks — Mon, 13 Oct 2025 10:45:31 +0000

Quantum pioneer: Michael Berry is best known for his work in the 1980s on the Berry Phase. (Courtesy: Michael Berry)

The theoretical physicist Michael Berry from the University of Bristol has won the 2025 Isaac Newton Medal and Prize for his “profound contributions across mathematical and theoretical physics in a career spanning over 60 years”. Presented by the Institute of Physics (IOP), which publishes Physics World, the international award is given annually for “world-leading contributions to physics by an individual of any nationality”.

Born in 1941 in Surrey, UK, Berry earned a BSc in physics from the University of Exeter in 1962 and a PhD from the University of St Andrews in 1965. He then moved to Bristol, where he has remained for the rest of his career.

Berry is best known for his work in the 1980s in which he showed that, under certain conditions, quantum systems can acquire what is known as a geometric phase. He was studying quantum systems in which the Hamiltonian describing the system is slowly changed so that it eventually returns to its initial form.

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Berry showed that the adiabatic theorem widely used to describe such systems was incomplete and that a system acquires a phase factor that depends on the path followed, but not on the rate at which the Hamiltonian is changed. This geometric phase factor is now known as the Berry phase.

Over his career Berry, has written some 500 papers across a wide number of topics. In physics, Berry’s ideas have applications in condensed matter, quantum information and high-energy physics, as well as optics, nonlinear dynamics, and atomic and molecular physics. In mathematics, meanwhile, his work forms the basis for research in analysis, geometry and number theory.

Berry told Physics World that the award is “unexpected recognition for six decades of obsessive scribbling…creating physics by seeking ‘claritons’ – elementary particles of sudden understanding – and evading ‘anticlaritons’ that annihilate them” as well as “getting insights into nature’s physics” such as studying tidal bores, tsunamis, rainbows and “polarised light in the blue sky”.

Over the years, Berry has won a wide number of other honours, including the IOP’s Dirac Medal and the Royal Medal from the Royal Society, both awarded in 1990. He was also given the Wolf Prize for Physics in 1998 and the 2014 Lorentz Medal from the Royal Netherlands Academy of Arts and Sciences. In 1996 he received a knighthood for his services to science.

Berry will also be a speaker at the IOP’s International Year of Quantum celebrations on 4 November.

Celebrating success

Berry’s latest honour forms part of the IOP’s wider 2025 awards, which recognize everyone from early-career scientists and teachers to technicians and subject specialists. Other winners include Julia Yeomans, who receives the Dirac Medal and Prize for her work highlighting the relevance of active physics to living matter.

Lok Yiu Wu, meanwhile, receives Jocelyn Bell Burnell Medal and Prize for her work on the development of a novel magnetic radical filter device, and for ongoing support of women and underrepresented groups in physics.

In a statement, IOP president Michele Dougherty congratulated all the winners. “It is becoming more obvious that the opportunities generated by a career in physics are many and varied – and the potential our science has to transform our society and economy in the modern world is huge,” says Dougherty. “I hope our winners appreciate they are playing an important role in this community, and know how proud we are to celebrate their successes.”

The full list of 2025 award winners is available here.

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Phase shift in optical cavities could detect low-frequency gravitational waves

No Author — Mon, 13 Oct 2025 08:00:54 +0000

A network of optical cavities could be used to detect gravitational waves (GWs) in an unexplored range of frequencies, according to researchers in the UK. Using technology already within reach, the team believes that astronomers could soon be searching for ripples in space–time across the milli-Hz frequency band at 10⁻⁵ Hz–1 Hz.

GWs were first observed a decade ago and since then the LIGO–Virgo–KAGRA detectors have spotted GWs from hundreds of merging black holes and neutron stars. These detectors work in the 10 Hz–30 kHz range. Researchers have also had some success at observing a GW background at nanohertz frequencies using pulsar timing arrays.

However, GWs have yet to be detected in the milli-Hz band, which should include signals from binary systems of white dwarfs, neutron stars, and stellar-mass black holes. Many of these signals would emanate from the Milky Way.

Several projects are now in the works to explore these frequencies, including the space-based interferometers LISA, Taiji, and TianQin; as well as satellite-borne networks of ultra-precise optical clocks. However, these projects are still some years away.

Multidisciplinary effort

Joining these efforts was a collaboration called QSNET, which was within the UK’s Quantum Technology for Fundamental Physics (QTFP) programme. “The QSNET project was a network of clocks for measuring the stability of fundamental constants,” explains Giovanni Barontini at the University of Birmingham. “This programme brought together physics communities that normally don’t interact, such as quantum physicists, technologists, high energy physicists, and astrophysicists.”

QTFP ended this year, but not before Barontini and colleagues had made important strides in demonstrating how milli-Hz GWs could be detected using optical cavities.

Inside an ultrastable optical cavity, light at specific resonant frequencies bounces constantly between a pair of opposing mirrors. When this resonant light is produced by a specific atomic transition, the frequency of the light in the cavity is very precise and can act as the ticking of an extremely stable clock.

“Ultrastable cavities are a main component of modern optical atomic clocks,” Barontini explains. “We demonstrated that they have reached sufficient sensitivities to be used as ‘mini-LIGOs’ and detect gravitational waves.”

When such GW passes through an optical cavity, the spacing between its mirrors does not change in any detectable way. However, QSNET results have led to Barontini’s team to conclude that milli-Hz GWs alter the phase of the light inside the cavity. What is more, they conclude that this effect would be detectable in the most precise optical cavities currently available.

“Methods from precision measurement with cold atoms can be transferred to gravitational-wave detection,” explains team member Vera Guarrera. “By combining these toolsets, compact optical resonators emerge as credible probes in the milli-Hz band, complementing existing approaches.”

Ground-based network

Their compact detector would comprise two optical cavities at 90° to each other – each operating at a different frequency – and an atomic reference at a third frequency. The phase shift caused by a passing gravitational wave is revealed in a change in how the three frequencies interfere with each other. The team proposes linking multiple detectors to create a global, ground-based network. This, they say, could detect a GW and also locate the position of its source in the sky.

By harnessing this existing technology, the researchers now hope that future studies could open up a new era of discovery of GWs in the milli-Hz range, far sooner than many projects currently in development.

“This detector will allow us to test astrophysical models of binary systems in our galaxy, explore the mergers of massive black holes, and even search for stochastic backgrounds from the early universe,” says team member Xavier Calmet at the University of Sussex. “With this method, we have the tools to start probing these signals from the ground, opening the path for future space missions.”

Barontini adds, “Hopefully this work will inspire the build-up of a global network of sensors that will scan the skies in a new frequency window that promises to be rich of sources – including many from our own galaxy,”.

The research is described in Classical and Quantum Gravity.

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The physics behind why cutting onions makes us cry

Michael Banks — Fri, 10 Oct 2025 14:30:46 +0000

Researchers in the US have studied the physics of how cutting onions can produce a tear-jerking reaction.

While it is known that volatile chemicals released from the onion – called propanethial S-oxide – irritate the nerves in the cornea to produce tears, how such chemical-laden droplets reach the eyes and whether they are influenced by the knife or cutting technique remain less clear.

To investigate, Sunghwan Jung from Cornell University and colleagues built a guillotine-like apparatus and used high-speed video to observe the droplets released from onions as they were cut by steel blades.

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“No one had visualized or quantified this process,” Jung told Physics World. “That curiosity led us to explore the mechanics of droplet ejection during onion cutting using high-speed imaging and strain mapping.”

They found that droplets, which can reach up to 60 cm high, were released in two stages – the first being a fast mist-like outburst that was followed by threads of liquid fragmenting into many droplets.

The most energetic droplets were released during the initial contact between the blade and the onion’s skin.

When they began varying the sharpness of the blade and the cutting speed, they discovered that a greater number of droplets were released by blunter blades and faster cutting speeds.

“That was even more surprising,” notes Jung. “Blunter blades and faster cuts – up to 40 m/s – produced significantly more droplets with higher kinetic energy.”

Another surprise was that refrigerating the onions prior to cutting also produced an increased number of droplets of similar velocity, compared to unchilled vegetables.

So if you want to reduce chances of welling up when making dinner, sharpen your knives, cut slowly and perhaps don’t keep the bulbs in the fridge.

The researchers say there are many more layers to the work and now plan to study how different onion varieties respond to cutting as well as how cutting could influence the spread of airborne pathogens such as salmonella.

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Motion blur brings a counterintuitive advantage for high-resolution imaging

Isabelle Dumé — Fri, 10 Oct 2025 08:00:51 +0000

Blur benefit: Images on the left were taken by a camera that was moving during exposure. Images on the right used the researchers’ algorithm to increase their resolution with information captured by the camera’s motion. (Courtesy: Pedro Felzenszwalb/Brown University)

Images captured by moving cameras are usually blurred, but researchers at Brown University in the US have found a way to sharpen them up using a new deconvolution algorithm. The technique could allow ordinary cameras to produce gigapixel-quality photos, with applications in biological imaging and archival/preservation work.

“We were interested in the limits of computational photography,” says team co-leader Rashid Zia, “and we recognized that there should be a way to decode the higher-resolution information that motion encodes onto a camera image.”

Conventional techniques to reconstruct high-resolution images from low-resolution ones involve relating low-res to high-res via a mathematical model of the imaging process. These effectiveness of these techniques is limited, however, as they produce only relatively small increases in resolution. If the initial image is blurred due to camera motion, this also limits the maximum resolution possible.

Exploiting the “tracks” left by small points of light

Together with Pedro Felzenszwalb of Brown’s computer science department, Zia and colleagues overcame these problems, successfully reconstructing a high-resolution image from one or several low-resolution images produced by a moving camera. The algorithm they developed to do this takes the “tracks” left by light sources as the camera moves and uses them to pinpoint precisely where the fine details must have been located. It then reconstructs these details on a finer, sub-pixel grid.

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“There was some prior theoretical work that suggested this shouldn’t be possible,” says Felzenszwalb. “But we show that there were a few assumptions in those earlier theories that turned out not to be true. And so this is a proof of concept that we really can recover more information by using motion.”

Application scenarios

When they tried the algorithm out, they found that it could indeed exploit the camera motion to produce images with much higher resolution than those without the motion. In one experiment, they used a standard camera to capture a series of images in a grid of high-resolution (sub-pixel) locations. In another, they took one or more images while the sensor was moving. They also simulated recording single images or sequences of pictures while vibrating the sensor and while moving it along a linear path. These scenarios, they note, could be applicable to aerial or satellite imaging. In both, they used their algorithm to construct a single high-resolution image from the shots captured by the camera.

“Our results are especially interesting for applications where one wants high resolution over a relatively large field of view,” Zia says. “This is important at many scales from microscopy to satellite imaging. Other areas that could benefit are super-resolution archival photography of artworks or artifacts and photography from moving aircraft.”

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The researchers say they are now looking into the mathematical limits of this approach as well as practical demonstrations. “In particular, we hope to soon share results from consumer camera and mobile phone experiments as well as lab-specific setups using scientific-grade CCDs and thermal focal plane arrays,” Zia tells Physics World.

“While there are existing systems that cameras use to take motion blur out of photos, no one has tried to use that to actually increase resolution,” says Felzenszwalb. “We’ve shown that’s something you could definitely do.”

The researchers presented their study at the International Conference on Computational Photography and their work is also available on the arXiv pre-print server.

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Hints of a boundary between phases of nuclear matter found at RHIC

No Author — Thu, 09 Oct 2025 15:30:37 +0000

In a major advance for nuclear physics, scientists on the STAR Detector at the Relativistic Heavy Ion Collider (RHIC) in the US have spotted subtle but striking fluctuations in the number of protons emerging from high-energy gold–gold collisions. The observation might be the most compelling sign yet of the long-sought “critical point” marking a boundary separating different phases of nuclear matter. This similar to how water can exist in liquid or vapour phases depending on temperature and pressure.

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Team member Frank Geurts at Rice University in the US tells Physics World that these findings could confirm that the “generic physics properties of phase diagrams that we know for many chemical substances apply to our most fundamental understanding of nuclear matter, too.”

A phase diagram maps how a substance transforms between solid, liquid, and gas. For everyday materials like water, the diagram is familiar, but the behaviour of nuclear matter under extreme heat and pressure remains a mystery.

Atomic nuclei are made of protons and neutrons tightly bound together. These protons and neutrons are themselves made of quarks that are held together by gluons. When nuclei are smashed together at high energies, the protons and neutrons “melt” into a fluid of quarks and gluons called a quark–gluon plasma. This exotic high-temperature state is thought to have filled the universe just microseconds after the Big Bang.

Smashing gold ions

The quark–gluon plasma is studied by accelerating heavy ions like gold nuclei to nearly the speed of light and smashing them together. “The advantage of using heavy-ion collisions in colliders such as RHIC is that we can repeat the experiment many millions, if not billions, of times,” Geurts explains.

By adjusting the collision energy, researchers can control the temperature and density of the fleeting quark–gluon plasma they create. This allows physicists to explore the transition between ordinary nuclear matter and the quark–gluon plasma. Within this transition, theory predicts the existence of a critical point where gradual change becomes abrupt.

Now, the STAR Collaboration has focused on measuring the minute fluctuations in the number of protons produced in each collision. These “proton cumulants,” says Geurts, are statistical quantities that “help quantify the shape of a distribution – here, the distribution of the number of protons that we measure”.

In simple terms, the first two cumulants correspond to the average and width of that distribution, while higher-order cumulants describe its asymmetry and sharpness. Ratios of these cumulants are tied to fundamental properties known as susceptibilities, which become highly sensitive near a critical point.

Unexpected discovery

Over three years of experiments, the STAR team studied gold–gold collisions at a wide range of energies, using sophisticated detectors to track and identify the protons and antiprotons created in each event. By comparing how the number of these particles changed with energy, the researchers discovered something unexpected.

As the collision energy decreased, the fluctuations in proton numbers did not follow a smooth trend. “STAR observed what it calls non-monotonic behaviour,” Geurts explains. “While at higher energies the ratios appear to be suppressed, STAR observes an enhancement at lower energies.” Such irregular changes, he said, are consistent with what might happen if the collisions pass near the critical point — the boundary separating different phases of nuclear matter.

For Volodymyr Vovchenko, a physicist at the University of Houston who was not involved in the research, the new measurements represent “a major step forward”. He says that “the STAR Collaboration has delivered the most precise proton-fluctuation data to date across several collision energies”.

Still, interpretation remains delicate. The corrections required to extract pure physical signals from the raw data are complex, and theoretical calculations lag behind in providing precise predictions for what should happen near the critical point.

“The necessary experimental corrections are intricate,” Vovchenko said, and some theoretical models “do not yet implement these corrections in a fully consistent way.” That mismatch, he cautions, “can blur apples-to-apples comparisons.”

The path forward

The STAR team is now studying new data from lower-energy collisions, focusing on the range where the signal appears strongest. The results could reveal whether the observed pattern marks the presence of a nuclear matter critical point or stems from more conventional effects.

Meanwhile, theorists are racing to catch up. “The ball now moves largely to theory’s court,” Vovchenko says. He emphasizes the need for “quantitative predictions across energies and cumulants of various order that are appropriate for apples-to-apples comparisons with these data.”

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Future experiments, including RHIC’s fixed-target program and new facilities such as the FAIR accelerator in Germany, will extend the search even further. By probing lower energies and producing vastly larger datasets, they aim to map the transition between ordinary nuclear matter and quark–gluon plasma with unprecedented precision.

Whether or not the critical point is finally revealed, the new data are a milestone in the exploration of the strong force and the early universe. As Geurts put it, these findings trace “landmark properties of the most fundamental phase diagram of nuclear matter,” bringing physicists one step closer to charting how everything – from protons to stars – first came to be.

The research is described in Physical Review Letters.

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From quantum curiosity to quantum computers: the 2025 Nobel Prize for Physics

Hamish Johnston — Thu, 09 Oct 2025 13:50:09 +0000

This year’s Nobel Prize for Physics went to John Clarke, Michel Devoret and John Martinis “for the discovery of macroscopic quantum mechanical tunnelling and energy quantization in an electric circuit”.

That circuit was a superconducting device called a Josephson junction and their work in the 1980s led to the development of some of today’s most promising technologies for quantum computers.

To chat about this year’s laureates, and the wide-reaching scientific and technological consequences of their work I am joined by Ilana Wisby – who is a quantum physicist, deep tech entrepreneur and former CEO of UK-based Oxford Quantum Circuits. We chat about the trio’s breakthrough and its influence on today’s quantum science and technology.

This podcast is supported by American Elements, the world’s leading manufacturer of engineered and advanced materials. The company’s ability to scale laboratory breakthroughs to industrial production has contributed to many of the most significant technological advancements since 1990 – including LED lighting, smartphones, and electric vehicles.

The post From quantum curiosity to quantum computers: the 2025 Nobel Prize for Physics appeared first on Physics World.

The power of physics: what can a physicist do in the nuclear energy industry?

Sarah Tesh — Thu, 09 Oct 2025 09:00:55 +0000

Nuclear power in the UK is on the rise – and so too are the job opportunities for physicists. Whether it’s planning and designing new reactors, operating existing plants safely and reliably, or dealing with waste management and decommissioning, physicists play a key role in the burgeoning nuclear industry.

The UK currently has nine operational reactors across five power stations, which together provided 12% of the country’s electricity in 2024. But the government wants that figure to reach 25% by 2050 as part of its goal to move away from fossil fuels and reach net zero. Some also think that nuclear energy will be vital for powering data centres for AI in a clean and efficient way.

While many see fusion as the future of nuclear power, it is still in the research and development stages, so fission remains where most job opportunities lie. Although eight of the current fleet of nuclear reactors are to be retired by the end of this decade, the first of the next generation are already in construction. At Hinkley Point C in Somerset, two new reactors are being built with costs estimated to reach £46bn; and in July 2025, Sizewell C in Suffolk got the final go-ahead.

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Rolls-Royce, meanwhile, has just won a government-funded bid to develop small modular reactors (SMR) in the UK. Although currently an unproven technology, the hope is that SMRs will be cheaper and quicker to build than traditional plants, with proponents saying that each reactor could produce enough affordable emission-free energy to power about 600,000 homes for at least 60 years.

The renaissance of the nuclear power industry has led to employment in the sector growing by 35% between 2021 and 2024, with the workforce reaching over 85,000. However – as highlighted in a 2025 members survey by the Nuclear Institute – there are concerns about a skills shortage. In fact, the Nuclear Skills Plan was detailed by the Nuclear Skills Delivery Group in 2024 with the aim to address this problem.

Supported by an investment of £763m by 2030 from the UK government and industry, the plan’s objectives include quadrupling the number of PhDs in nuclear fission, and doubling the number of graduates entering the workforce. It also aims to provide opportunities for people to “upskill” and join the sector mid-career. The overall hope is to fill 40,000 new jobs by the end of the decade.

Having a degree in physics can open the door to any part of the nuclear-energy industry, from designing, operating or decommissioning a reactor, to training staff, overseeing safety or working as a consultant. We talk to six nuclear experts who all studied physics at university but now work across the sector, for a range of companies – including EDF Energy and Great British Energy–Nuclear. They give a quick snapshot of their “nuclear journeys”, and offer advice to those thinking of following in their footsteps.

Design and construction

(Courtesy: Michael Hodgson)

Michael Hodgson, lead engineer, Rolls-Royce SMR

My interest in nuclear power started when I did a project on energy at secondary school. I learnt that there were significant challenges around the world’s future energy demands, resource security, and need for clean generation. Although at the time these were not topics commonly talked about, I could see they were vital to work on, and thought nuclear would play an important role.

I went on to study physics at the University of Surrey, with a year at Michigan State University in the US and another at CERN. After working for a couple of years, I returned to Surrey to do a part-time masters in radiation detection and instrumentation, followed a few years later by a PhD in radiation-hard semiconductor neutron detectors.

Up until recently, my professional work has mainly been in the supply chain for nuclear applications, working for Thermo Fisher Scientific, Centronic and Exosens. Nuclear power isn’t made by one company, it’s a combination of thousands of suppliers and sub-suppliers, the majority of which are small to medium-sized enterprises that need to operate across multiple industries. My job was primarily a technical design authority for manufacturers of radiation detectors and instruments, used in applications such as reactor power monitoring, health physics, industrial controls, and laboratory equipment, to name but a few. Now I work at Rolls-Royce SMR as a lead engineer for the control and instrumentation team. This role involves selecting and qualifying the thousands of different detectors and control instruments that will support the operation of small modular reactors.

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Logical, evidence-based problem solving is the cornerstone of science and a powerful tool in any work setting
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Beyond the technical knowledge I’ve gained throughout my education, studying physics has also given me two important skills. Firstly, learning how to learn – this is critical in academia but it also helps you step into any professional role. The second skill is the logical, evidence-based problem solving that is the cornerstone of science, which is a powerful tool in any work setting.

A career in nuclear energy can take many forms. The industry is comprised of a range of sectors and thousands of organizations that altogether form a complex support structure. My advice for any role is that knowledge is important, but experience is critical. While studying, try to look for opportunities to gain professional experience – this may be industry placements, research projects, or even volunteering. And it doesn’t have to be in your specific area of interest – cross-disciplinary experience breeds novel thinking. Utilizing these opportunities can guide your professional interests, set your CV apart from your peers, and bring pragmatism to your future roles.

Reactor operation

(Courtesy: Katie Barber)

Katie Barber, nuclear reactor operator and simulator instructor at Sizewell B, EDF

I studied physics at the University of Leicester simply because it was a subject I enjoyed – at the time I had no idea what I wanted to do for a career. I first became interested in nuclear energy when I was looking for graduate jobs. The British Energy (now EDF) graduate scheme caught my eye because it offered a good balance of training and on-the-job experience. I was able to spend time in multiple different departments at different power stations before I decided which career path was right for me.

At the end of my graduate scheme, I worked in nuclear safety for several years. This involved reactor physics testing and advising on safety issues concerning the core and fuel. It was during that time I became interested in the operational response to faults. I therefore applied for the company’s reactor operator training programme – a two-year course that was a mixture of classroom and simulator training. I really enjoyed being a reactor operator, particularly during outages when the plant would be shutdown, cooled, depressurised and dissembled for refuelling before reversing the process to start up again. But after almost 10 years in the control room, I wanted a new challenge.

Now I develop and deliver the training for the control-room teams. My job, which includes simulator and classroom training, covers everything from operator fundamentals (such as reactor physics and thermodynamics) and normal operations (e.g. start up and shutdown), through to accident scenarios.

My background in physics gives me a solid foundation for understanding the reactor physics and thermodynamics of the plant. However, there are also a lot of softer skills essential for my role. Teaching others requires the ability to present and explain technical material; to facilitate a constructive debrief after a simulator scenario; and to deliver effective coaching and feedback. The training focuses as much on human performance as it does technical knowledge, highlighting the importance of effective teamwork, error prevention and clear communications.

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A graduate training scheme is an excellent way to get an overview of the business, and gain experience across many different departments and disciplines
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With Hinkley Point C construction progressing well and the recent final investment decision for Sizewell C, now is an exciting time to join the nuclear industry. A graduate training scheme is an excellent way to get an overview of the business, and gain experience across many different departments and disciplines, before making the decision about which area is right for you.

Nuclear safety

(Courtesy: Jacob Plummer)

Jacob Plummer, principal nuclear safety inspector, Office for Nuclear Regulation

I’d been generally interested in nuclear science throughout my undergraduate physics degree at the University of Manchester, but this really accelerated after studying modules in applied nuclear and reactor physics. The topic was engaging, and the nuclear industry offered a way to explore real-world implementation of physics concepts. This led me to do a masters in nuclear science and technology, also at Manchester (under the Nuclear Technology Education Consortium), to develop the skills the UK nuclear sector required.

My first job was as a graduate nuclear safety engineer at Atkins (now AtkinsRealis), an engineering consultancy. It opened my eyes to the breadth of physics-related opportunities in the industry. I worked on new and operational power station projects for Hitachi-GE and EDF, as well as a variety of defence new-build projects. I primarily worked in hazard analysis, using modelling and simulation tools to generate evidence on topics like fire, blast and flooding to support safety case claims and inform reactor designs. I was also able to gain experience in project management, business development, and other energy projects, such as offshore wind farms. The analytical and problem solving skills I had developed during my physics studies really helped me to adapt to all of these roles.

Currently I work as a principal nuclear safety inspector at the Office for Nuclear Regulation. My role is quite varied. Day to day I might be assessing safety case submissions from a prospective reactor vendor; planning and delivering inspections at fuel and waste sites; or managing fire research projects as part of an international programme. A physics background helps me to understand complex safety arguments and how they link to technical evidence; and to make reasoned and logical regulatory judgements as a result.

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Physics skills and experience are valued across the nuclear industry, from hazards and fault assessment to security, safeguards, project management and more
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It’s a great time to join the nuclear industry with a huge amount of activity and investment across the nuclear lifecycle. I’d advise early-career professionals to cast the net wide when looking for roles. There are some obvious physics-related areas such as health physics, fuel and core design, and criticality safety, but physics skills and experience are valued across the nuclear industry, from hazards and fault assessment to security, safeguards, project management and more. Don’t be limited by the physicist label.

Waste and decommissioning

(Courtesy: Egis)

Becky Houghton, principal consultant, Galson Sciences Ltd

My interest in a career in nuclear energy sparked mid-way through my degree in physics and mathematics at the University of Sheffield, when I was researching “safer nuclear power” for an essay. Several rabbit holes later, I had discovered a myriad of opportunities in the sector that would allow me to use the skills and knowledge I’d gained through my degree in an industrial setting.

My first job in the field was as a technical support advisor on a graduate training scheme, where I supported plant operations on a nuclear licensed site. Next, I did a stint working in strategy development and delivery across the back end of the fuel cycle, before moving into consultancy. I now work as a principal consultant for Galson Sciences Ltd, part of the Egis group. Egis is an international multi-disciplinary consulting and engineering firm, within which Galson Sciences provides specialist nuclear decommissioning and waste management consultancy services to nuclear sector clients worldwide.

Ultimately, my role boils down to providing strategic and technical support to help clients make decisions. My focus these days tends to be around radioactive waste management, which can mean anything from analysing radioactive waste inventories to assessing the environmental safety of disposal facilities.

In terms of technical skills needed for the role, data analysis and the ability to provide high-quality reports on time and within budget are at the top of the list. Physics-wise, an understanding of radioactive decay, criticality mechanisms and the physico-chemical properties of different isotopes are fairly fundamental requirements. Meanwhile, as a consultant, some of the most important soft skills are being able to lead, teach and mentor less experienced colleagues; develop and maintain strong client relationships; and look after the well-being and deployment of my staff.

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Whichever part of the nuclear fuel cycle you end up in, the work you do makes a difference
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My advice to anyone looking to go into the nuclear energy is to go for it. There are lots of really interesting things happening right now across the industry, all the way from building new reactors and operating the current fleet, to decommissioning, site remediation and waste management activities. Whichever part of the nuclear fuel cycle you end up in, the work you do makes a difference, whether that’s by cleaning up the legacy of years gone by or by helping to meet the UK’s energy demands. Don’t be afraid to say “yes” to opportunities even if they’re outside your comfort zone, keep learning, and keep being curious about the world around you.

Uranium enrichment

(Courtesy: Mark Savage)

Mark Savage, nuclear licensing manager, Urenco UK

As a child, I remember going to the visitors’ centre at the Sellafield nuclear site – a large nuclear facility in the north-west of England that’s now the subject of a major clean-up and decommissioning operation. At the centre, there was a show about splitting the atom that really sparked my interest in physics and nuclear energy.

I went on to study physics at Durham University, and did two summer placements at Sellafield, working with radiometric instruments. I feel these placements helped me get a place on the Rolls-Royce nuclear engineering graduate scheme after university. From there I joined Urenco, an international supplier of uranium enrichment services and fuel cycle products for the civil nuclear industry.

While at Urenco, I have undertaken a range of interesting roles in nuclear safety and radiation physics, including criticality safety assessment and safety case management. Highlights have included being the licensing manager for a project looking to deploy a high-temperature gas-cooled reactor design, and presenting a paper at a nuclear industry conference in Japan. These roles have allowed me to directly apply my physics background – such as using Monte Carlo radiation transport codes to model nuclear systems and radiation sources – as well as develop broader knowledge and skills in safety, engineering and project management.

My current role is nuclear licensing manager at the Capenhurst site in Cheshire, where we operate a number of nuclear facilities including three uranium enrichment plants, a uranium chemical deconversion facility, and waste management facilities. I lead a team who ensure the site complies with regulations, and achieves the required approvals for our programme of activities. Key skills for this role include building relationships with internal and external stakeholders; being able to understand and explain complex technical issues to a range of audiences; and planning programmes of work.

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I would always recommend anyone interested in working in nuclear energy to look for work experience
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Some form of relevant experience is always advantageous, so I would always recommend anyone interested in working in nuclear energy to look for work experience visits, summer placements or degree schemes that include working with industry.

Skills initiatives

(Courtesy: Great British Energy – Nuclear)

Saralyn Thomas, skills lead, Great British Energy – Nuclear

During my physics degree at the University of Bristol, my interest in energy led me to write a dissertation on nuclear power. This inspired me to do a masters in nuclear science and technology at the University of Manchester under the Nuclear Technology Education Consortium. The course opened doors for me, such as a summer placement with the UK National Nuclear Laboratory, and my first role as a junior safety consultant with Orano.

I worked in nuclear safety for roughly 10 years, progressing to principal consultant with Abbott Risk Consulting, but decided that this wasn’t where my strengths and passions lay. During my career, I volunteered for the Nuclear Institute (NI), and worked with the society’s young members group – the Young Generation Network (YGN). I ended up becoming chair of the YGN and a trustee of the NI, which involved supporting skills initiatives including those feeding into the Nuclear Skills Plan. Having a strategic view of the sector and helping to solve its skills challenges energized me in a new way, so I chose to change career paths and moved to Great British Energy – Nuclear (GBE-N) as skills lead. In this role I plan for what skills the business and wider sector will need for a nuclear new build programme, as well as develop interventions to address skills gaps.

GBE-N’s current remit is to deliver Europe’s first fleet of small modular reactors, but there is relatively limited experience of building this technology. Problem-solving skills from my background in physics have been essential to understanding what assumptions we can put in place at this early stage, learning from other nuclear new builds and major infrastructure projects, to help set us up for the future.

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The UK’s nuclear sector is seeing significant government commitment, but there is a major skills gap
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To anyone interested in nuclear energy, my advice is to get involved now. The UK’s nuclear sector is seeing significant government commitment, but there is a major skills gap. Nuclear offers a lifelong career with challenging, complex projects – ideal for physicists who enjoy solving problems and making a difference.

The post The power of physics: what can a physicist do in the nuclear energy industry? appeared first on Physics World.

A record-breaking anisotropic van der Waals crystal?

Paul Mabey — Thu, 09 Oct 2025 08:13:03 +0000

In general, when you measure material properties such as optical permittivity, your measurement doesn’t depend on the direction in which you make it.

However, recent research has shown that this is not the case for all materials. In some cases, their optical permittivity is directional. This is commonly known as in-plane optical anisotropy. A larger difference between optical permittivity in different directions means a larger anisotropy.

Materials with very large anisotropies have applications in a wide range of fields from photonics and electronics to medical imaging. However, for most materials remains available today, the value remains relatively low.

These potential applications combined with the current limitation has driven a large amount of research into novel anisotropic materials.

In this latest work, a team of researchers studied the quasi-one-dimensional van der Waals crystal: Ta₂NiSe₅.

Van der Waals (vdW) crystals are made up of chains, ribbons, or layers of atoms that stick together through weak van der Waals forces.

In quasi-one-dimensional vdW crystals, the atoms are strongly connected along one direction, while the connections in the other directions are much weaker, making their properties very direction-dependent.

This structure makes quasi-one-dimensional vdW crystals a good place to search for large optical anisotropy values. The researchers studied the new crystal by using a range of measurement techniques such as ellipsometry and spectroscopy as well as state of the art first principles computer simulations.

The results show that Ta₂NiSe₅ has a record-breaking in-plane optical anisotropy across the visible to infrared spectral region, representing the highest value reported among van der Waals materials to date.

The study therefore has large implications for next-generation devices in photonics and beyond.

Read the full article

Giant in-plane anisotropy in novel quasi-one-dimensional van der Waals crystal – IOPscience

Zhou et al. 2025 Rep. Prog. Phys. 88 050502

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Unlocking the limits of quantum security

Lorna Brigham — Thu, 09 Oct 2025 08:12:56 +0000

In quantum information theory, secret-key distillation is a crucial process for enabling secure communication across quantum networks. It works by extracting confidential bits from shared quantum states or channels using local operations and limited classical communication, ensuring privacy even over insecure links.

A bipartite quantum state is a system shared between two parties (often called Alice and Bob) that may exhibit entanglement. If they successfully distil a secret key, they can encrypt and decrypt messages securely, using the key like a shared password known only to them.

To achieve this, Alice and Bob use point-to-point quantum channels and perform local operations, meaning each can only manipulate their own part of the system. They also rely on one-way classical communication, where Alice sends messages to Bob, but Bob cannot reply. This constraint reflects realistic limitations in quantum networks and helps researchers identify the minimum requirements for secure key generation.

This paper investigates how many secret bits can be extracted under these conditions. The authors introduce a resource-theoretic framework based on unextendible entanglement which is a form of entanglement that cannot be shared with additional parties. This framework allows them to derive efficiently computable upper bounds on secret-key rates, helping determine how much security is achievable with limited resources.

Their results apply to both one-shot scenarios, where the quantum system is used only once, and asymptotic regimes, where the same system is used repeatedly and statistical patterns emerge. Notably, they extend their approach to quantum channels assisted by forward classical communication, resolving a long-standing open problem about the one-shot forward-assisted private capacity.

Finally, they show that error rates in private communication can decrease exponentially with repeated channel use, offering a scalable and practical path toward building secure quantum messaging systems.

Read the full article

Extendibility limits quantum-secured communication and key distillation

Vishal Singh and Mark M Wilde 2025 Rep. Prog. Phys. 88 067601

Do you want to learn more about this topic?

Distribution of entanglement in large-scale quantum networks by S Perseguers, G J Lapeyre Jr, D Cavalcanti, M Lewenstein and A Acín (2013)

The post Unlocking the limits of quantum security appeared first on Physics World.

Optical gyroscope detects Earth’s rotation with the highest precision yet

Isabelle Dumé — Wed, 08 Oct 2025 16:11:55 +0000

As the Earth moves through space, it wobbles. Researchers in Germany have now directly observed this wobble with the highest precision yet thanks to a large ring laser gyroscope they developed for this purpose. The instrument, which is located in southern Germany and operates continuously, represents an important advance in the development of super-sensitive rotation sensors. If further improved, such sensors could help us better understand the interior of our planet and test predictions of relativistic effects, including the distortion of space-time due to Earth’s rotation.

The Earth rotates once every day, but there are tiny fluctuations, or wobbles, in its axis of rotation. These fluctuations are caused by several factors, including the gravitational forces of the Moon and Sun and, to a lesser extent, the neighbouring planets in our Solar System. Other, smaller fluctuations stem from the exchange of momentum between the solid Earth and the oceans, atmosphere and ice sheets. The Earth’s shape, which is not a perfect sphere but is flattened at the poles and thickened at the equator, also contributes to the wobble.

These different types of fluctuations produce effects known as precession and nutation that cause the extension of the Earth’s axis to trace a wrinkly circle in the sky. At the moment, this extended axis is aligned precisely with the North Star. In the future, it will align with other stars before returning to the North Star again in a cycle that lasts 26,000 years.

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Most studies of the Earth’s rotation involve combining data from many sources. These sources include very long baseline radio-astronomy observations of quasars; global satellite navigation systems (GNSS); and GNSS observations combined with satellite laser ranging (SLR) and Doppler orbitography and radiopositioning integrated by satellite (DORIS). These techniques are based on measuring the travel time of light, and because it is difficult to combine them, only one such measurement can be made per day.

An optical interferometer that works using the Sagnac effect

The new gyroscope, which is detailed in Science Advances, is an optical interferometer that operates using the Sagnac effect. At its heart is an optical cavity that guides a light beam around a square path 16 m long. Depending on the rate of rotation it experiences, this cavity selects two different frequencies from the beam to be coherently amplified. “The two frequencies chosen are the only ones that have an integer number of waves around the cavity,” explains team leader Ulrich Schreiber of the Technische Universität München (TUM). “And because of the finite velocity of light, the co-rotating beam ‘sees’ a slightly larger cavity, while the anti-rotating beam ‘sees’ a slightly shorter one.”

The frequency shift in the interference pattern produced by the co-rotating beam is projected onto an external detector and is strictly proportional to the Earth’s rotation rate. Because the accuracy of the measurement depends, in part, on the mechanical stability of the set-up, the researchers constructed their gyroscope from a glass ceramic that does not expand much with temperature. They also set it up horizontally in an underground laboratory, the Geodetic Observatory Wettzell in southern Bavaria, to protect it as much as possible from external vibrations.

The instrument can sense the Earth’s rotation to within an accuracy of 48 parts per billion (ppb), which corresponds to picoradians per second. “This is about a factor of 100 better than any other rotation sensor,” says Schreiber, “and, importantly, is less than an order of magnitude away from the regime in which relativistic effects can be measured – but we are not quite there yet.”

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An increase in the measurement accuracy and stability of the ring laser by a factor of 10 would, Schreiber adds, allow the researchers to measure the space-time distortion caused by the Earth’s rotation. For example, it would permit them to conduct a direct test for the Lense-Thirring effect — that is, the “dragging” of space by the Earth’s rotation – right at the Earth’s surface.

To reach this goal, the researchers say they would need to amend several details of their sensor design. One example is the composition of the thin-film coatings on the mirrors inside their optical interferometer. “This is neither easy nor straightforward,” explains Schreiber, “but we have some ideas to try out and hope to progress here in the near future.

“In the meantime, we are working towards implementing our measurements into a routine evaluation procedure,” he tells Physics World.

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Susumu Kitagawa, Richard Robson and Omar Yaghi win the 2025 Nobel Prize for Chemistry

Michael Banks — Wed, 08 Oct 2025 10:01:16 +0000

Susumu Kitagawa, Richard Robson and Omar Yaghi have been awarded the 2025 Nobel Prize for Chemistry “for developing metal-organic frameworks”.

The award includes a SEK 11m prize ($1.2m), which is shared equally by the winners. The prize will be presented at a ceremony in Stockholm on 10 December.

The prize was announced this morning by members of the Royal Swedish Academy of Science. Speaking on the phone during the press conference, Kitagawa noted that he was “deeply honoured and delighted” that his research had been recognized.

A new framework

Beginning in the late 1980s and for the next couple of decades, the trio, who are all trained chemists, developed a new form of molecular architecture in that metal ions function as cornerstones that are linked by long organic carbon-based molecules.

Together, the metal ions and molecules form crystals that contain large cavities through which gases and other chemicals can flow.

“It’s a little like Hermione’s handbag – small on the outside, but very large on the inside,” noted Heiner Linke, chair of the Nobel Committee for Chemistry.

Yet the trio had to overcome several challenges before they could be used such as making them stable and flexible, which Kitagawa noted “was very tough”.

These porous materials are now called metal-organic frameworks (MOF). By varying the building blocks used in the MOFs, researchers can design them to capture and store specific substances as well as drive chemical reactions or conduct electricity.

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“Metal-organic frameworks have enormous potential, bringing previously unforeseen opportunities for custom-made materials with new functions,” added Linke.

Following the laureates’ work, chemists have built tens of thousands of different MOFs.

3D MOFs are an important class of materials that could be used in applications as diverse as sensing, gas storage, catalysis and optoelectronics.

MOFs are now able to capture water from air in the desert, sequester carbon dioxide from industry effluents, store hydrogen gas, recover rare-earth metals from waste, break down oil contamination as well as extract “forever chemicals” such as PFAS from water.

“My dream is to capture air and to separate air into CO₂, oxygen and water and convert them to usable materials using renewable energy,” noted Kitagawa.

Their 2D versions might even be used as flexible material platforms to realize exotic quantum phases, such as topological and anomalous quantum Hall insulators.

Life scientific

Kitagawa was born in 1951 in Kyoto, Japan. He obtained a PhD from Kyoto University, Japan, in 1979 and then held positions at Kindai University before joining Tokyo Metropolitan University in 1992. He then joined Kyoto University in 1998 where he is currently based.

Robson was born in 1937 in Glusburn, UK. He obtained a PhD from University of Oxford in 1962. After postdoc positions at California Institute of Technology and Stanford University, in 1966 he moved to the University of Melbourne where he remained for the rest of his career.

Yaghi was born in 1965 in Amman, Jordan. He obtained a PhD from University of Illinois Urbana-Champaign, US, in 1990. He then held positions at Arizona State University, the University of Michigan and the University of California, Los Angeles, before joining the University of California, Berkeley, in 2012 where he is currently based.

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