Physics World

Physicists overcome ‘acoustic collapse’ to levitate multiple objects with sound

Isabelle Dumé — Wed, 07 Jan 2026 09:00:35 +0000

Sound waves can make small objects hover in the air, but applying this acoustic levitation technique to an array of objects is difficult because the objects tend to clump together. Physicists at the Institute of Science and Technology Austria (ISTA) have now overcome this problem thanks to hybrid structures that emerge from the interplay between attractive acoustic forces and repulsive electrostatic ones. By proving that it is possible to levitate many particles while keeping them separated, the finding could pave the way for advances in acoustic-levitation-assisted 3D printing, mid-air chemical synthesis and micro-robotics.

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In acoustic levitation, particles ranging in size from tens of microns to millimetres are drawn up into the air and confined by an acoustic force. The origins of this force lie in the momentum that the applied acoustic field transfers to a particle as sound waves scatter off its surface. While the technique works well for single particles, multiple particles tend to aggregate into a single dense object in mid-air because the acoustic forces they scatter can, collectively, create an attractive interaction between them.

Keeping particles separated

Led by Scott Waitukaitis, the ISTA researchers found a way to avoid this so-called “acoustic collapse” by using a tuneable repulsive electrostatic force to counteract the attractive acoustic one. They began by levitating a single silver-coated poly(methyl methacrylate) (PMMA) microsphere 250‒300 µm in diameter above a reflector plate coated with a transparent and conductive layer of indium tin oxide (ITO). They then imbued the particle with a precisely controlled amount of electrical charge by letting it rest on the ITO plate with the acoustic field off, but with a high-voltage DC potential applied between the plate and a transducer. This produces a capacitive build-up of charge on the particle, and the amount of charge can be estimated from Maxwell’s solutions for two contacting conductive spheres (assuming, in the calculations, that the lower plate acts like a sphere with infinite radius).

The next step in the process is to switch on the acoustic field and, after just 10 ms, add the electric field to it. During the short period in which both fields are on, and provided the electric field is strong enough, either field is capable of launching the particle towards the centre of the levitation setup. The electric fields is then switched off. A few seconds later, the particle levitates stably in the trap, with a charge given, in principle, by Maxwell’s approximations.

A visually mesmerizing dance of particles

This charging method works equally well for multiple particles, allowing the researchers to load particles into the trap with high efficiency and virtually any charge they want, limited only by the breakdown voltage of the surrounding air. Indeed, the physicists found they could tune the charge to levitate particles separately or collapse them into a single, dense object. They could even create hybrid states that mix separated and collapsed particles.

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And that wasn’t all. According to team member Sue Shi, a PhD student at ISTA and the lead author of a paper in PNAS about the research, the most exciting moment came when they saw the compact parts of the hybrid structures spontaneously begin to rotate, while the expanded parts remained in one place while oscillating in response to the rotation. The result was “a visually mesmerizing dance,” Shi says, adding that “this is the first time that such acoustically and electrostatically coupled interactions have been observed in an acoustically levitated system.”

As well as having applications in areas such as materials science and micro-robotics, Shi says the technique developed in this work could be used to study non-reciprocal effects that lead to the particles rotating or oscillating. “This would pave the way for understanding more elusive and complex non-reciprocal forces and many-body interactions that likely influence the behaviours of our system,” Shi tells Physics World.

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When heat moves sideways

Lorna Brigham — Wed, 07 Jan 2026 08:30:17 +0000

Heat travels across a metal by the movement of electrons. However, in an insulator there are no free charge carriers; instead, vibrations in the atoms (phonons) move the heat from hot regions to cool regions in a straight path. In some materials, when a magnetic field is applied, the phonons begin to move sideways, this is known as the Phonon Hall Effect. Quantised collective excitations of the spin structure, called magnons, can also do this via the Magnon Hall Effect. A combined effect occurs when magnons and phonons strongly interact and traverse sideways in the Magnon–Polaron Hall Effect.

Scientists understand the quantum mechanical property known as Berry curvature that causes this transverse heat flow. Yet in some materials, the effect is greater than what Berry curvature alone can explain. In this research, an exceptionally large thermal Hall effect is recorded in MnPS₃, an insulating antiferromagnetic material with strong magnetoelastic coupling and a spin-flop transition. The thermal Hall angle remains large down to 4 K and cannot be accounted for by standard Berry curvature-based models.

This work provides an in-depth analysis of the role of the spin-flop transition in MnPS₃’s thermal properties and highlights the need for new theoretical approaches to understand magnon–phonon coupling and scattering. Materials with large thermal Hall effects could be used to control heat in nanoscale devices such as thermal diodes and transistors.

Read the full article

Large thermal Hall effect in MnPS3

Mohamed Nawwar et al 2025 Rep. Prog. Phys. 88 080503

Do you want to learn more about this topic?

Quantum-Hall physics and three dimensions Johannes Gooth, Stanislaw Galeski and Tobias Meng (2023)

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Symmetry‑preserving route to higher‑order insulators

Lorna Brigham — Wed, 07 Jan 2026 08:29:08 +0000

Topological insulators are materials that are insulating in the bulk within the bandgap, yet exhibit conductive states on their surface at frequencies within that same bandgap. These surface states are topologically protected, meaning they cannot be easily disrupted by local perturbations. In general, a material of n‑dimensions can host n‑1-dimensional topological boundary states. If the symmetry protecting these states is further broken, a bandgap can open between the n-1-dimensional states, enabling the emergence of n-2-dimensional topological states. For example, a 3D material can host 2D protected surface states, and breaking additional symmetry can create a bandgap between these surface states, allowing for protected 1D edge states. A material undergoing such a process is said to exhibit a phenomenon known as a higher-order topological insulator. In general, higher-order topological states appear in dimensions one lower than the parent topological phase due to the further unit-cell symmetry reduction. This requires at least a 2D lattice for second-order states, with the maximal order in 3D systems being three.

The researchers here introduce a new method for repeatedly opening the bandgap between topological states and generating new states within those gaps in an unbounded manner – without breaking symmetries or reducing dimensions. Their approach creates hierarchical topological insulators by repositioning domain walls between different topological regions. This process opens bandgaps between original topological states while preserving symmetry, enabling the formation of new hierarchical states within the gaps. Using one‑ and two‑dimensional Su–Schrieffer–Heeger models, they show that this procedure can be repeated to generate multiple, even infinite, hierarchical levels of topological states, exhibiting fractal-like behavior reminiscent of a Matryoshka doll. These higher-level states are characterized by a generalized winding number that extends conventional topological classification and maintains bulk-edge correspondence across hierarchies.

The researchers confirm the existence of second‑ and third-level domain‑wall and edge states and demonstrate that these states remain robust against perturbations. Their approach is scalable to higher dimensions and applicable not only to quantum systems but also to classical waves such as phononics. This broadens the definition of topological insulators and provides a flexible way to design complex networks of protected states. Such networks could enable advances in electronics, photonics, and phonon‑based quantum information processing, as well as engineered structures for vibration control. The ability to design complex, robust, and tunable hierarchical topological states could lead to new types of waveguides, sensors, and quantum devices that are more fault-tolerant and programmable.

Read the full article

Hierarchical topological states without dimension reduction

Joel R Pyfrom et al 2025 Rep. Prog. Phys. 88 118003

Do you want to learn more about this topic?

Interacting topological insulators: a review by Stephan Rachel (2018)

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New hybrid state of matter is a mix of solid and liquid

Isabelle Dumé — Tue, 06 Jan 2026 15:00:44 +0000

The boundary between a substance’s liquid and solid phases may not be as clear-cut as previously believed. A new state of matter that is a hybrid of both has emerged in research by scientists at the University of Nottingham, UK and the University of Ulm, Germany, and they say the discovery could have applications in catalysis and other thermally-activated processes.

In liquids, atoms move rapidly, sliding over and around each other in a random fashion. In solids, they are fixed in place. The transition between the two states, solidification, occurs when random atomic motion transitions to an ordered crystalline structure.

At least, that’s what we thought. Thanks to a specialist microscopy technique, researchers led by Nottingham’s Andrei Khlobystov found that this simple picture isn’t entirely accurate. In fact, liquid metal nanoparticles can contain stationary atoms – and as the liquid cools, their number and position play a significant role in solidification.

Some atoms remain stationary

The team used a method called spherical and chromatic aberration-corrected high-resolution transmission electron microscopy (Cc/Cs-corrected HRTEM) at the low-voltage SALVE instrument at Ulm to study melted metal nanoparticles (such as platinum, gold and palladium) deposited on an atomically thin layer of graphene. This carbon-based material acted a sort of “hob” for heating the particles, says team member Christopher Leist, who was in charge of the HRTEM experiments. “As they melted, the atoms in the nanoparticles began to move rapidly, as expected,” Leist says. “To our surprise, however, we found that some atoms remained stationary.”

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At high temperatures, these static atoms bind strongly to point defects in the graphene support. When the researchers used the electron beam from the transmission microscope to increase the number of these defects, the number of stationary atoms within the liquid increased, too. Khlobystov says that this had a knock-on effect on how the liquid solidified: when the stationary atoms are few in number, a crystal forms directly from the liquid and continues to grow until the entire particle has solidified. When their numbers increase, the crystallization process cannot take place and no crystals form.

“The effect is particularly striking when stationary atoms create a ring (corral) that surrounds and confines the liquid,” he says. “In this unique state, the atoms within the liquid droplet are in motion, while the atoms forming the corral remain motionless, even at temperatures well below the freezing point of the liquid.”

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Unprecedented level of detail

The researchers chose to use Cc/Cs-corrected HRTEM in their study because minimizing spherical and chromatic aberrations through specialized hardware installed on the microscope enabled them to resolve single atoms in their images.

“Additionally, we can control both the energy of the electron beam and the sample temperature (the latter using MEMS-heated chip technology),” Khlobystov explains. “As a result, we can study metal samples at temperatures of up to 800 °C, even in a molten state, without sacrificing atomic resolution. We can therefore observe atomic behaviour during crystallization while actively manipulating the environment around the metal particles using the electron beam or by cooling the particles. This level of detail under such extreme conditions is unprecedented.”

Effect could be harnessed for catalysis

The Nottingham-Ulm researchers, who report their work in ACS Nano, say they obtained their results by chance while working on an EPSRC-funded project on 1-2 nm metal particles for catalysis applications. “Our approach involves assembling catalysts from individual metal atoms, utilizing on-surface phenomena to control their assembly and dynamics,” explains Khlobystov. “To gain this control, we needed to investigate the behaviour of metal atoms at varying temperatures and within different local environments on a support material.

“We suspected that the interplay between vacancy defects in the support and the sample temperature creates a powerful mechanism for controlling the size and structure of the metal particles,” he tells Physics World. “Indeed, this study revealed the fundamental mechanisms behind this process with atomic precision.”

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The experiments were far from easy, he recalls, with one of the key challenges being to identify a thin, robust and thermally conductive support material for the metal. Happily, graphene meets all these criteria.

“Another significant hurdle to overcome was to be able to control the number of defect sites surrounding each particle,” he adds. “We successfully accomplished this by using the TEM’s electron beam not just as an imaging tool, but also as a means to modify the environment around the particles by creating defects.”

The researchers say they would now like to explore whether the effect can be harnessed for catalysis. To do this, Khlobystov says it will be essential to improve control over defect production and its scale. “We also want to image the corralled particles in a gas environment to understand how the phenomenon is influenced by reaction conditions, since our present measurements were conducted in a vacuum,” he adds.

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A theoretical physicist’s journey through the food and drink industry

No Author — Tue, 06 Jan 2026 11:00:16 +0000

Rob Farr is a theorist and computer modeller whose career has taken him down an unconventional path. He studied physics at the University of Cambridge, UK, from 1991 to 1994, staying on to do a PhD in statistical physics. But while many of his contemporaries then went into traditional research fields – such as quantum science, high-energy physics and photonic technologies – Farr got a taste for the food and drink manufacturing industry. It’s a multidisciplinary field in which Farr has worked for more than 25 years.

After leaving academia in 1998, first stop was Unilever’s €13bn foods division. For two decades, latterly as a senior scientist, Farr guided R&D teams working across diverse lines of enquiry – “doing the science, doing the modelling”, as he puts it. Along the way, Farr worked on all manner of consumer products including ice-cream, margarine and non-dairy spreads, as well as “dry” goods such as bouillon cubes. There was also the occasional foray into cosmetics, skin creams and other non-food products.

As a theoretical physicist working in industrial-scale food production, Farr’s focus has always been on the materials science of the end-product and how it gets processed. “Put simply,” says Farr, “that means making production as efficient as possible – regarding both energy and materials use – while developing ‘new customer experiences’ in terms of food taste, texture and appearance.”

Ice-cream physics

One tasty multiphysics problem that preoccupied Farr for a good chunk of his time at Unilever is ice cream. It is a hugely complex material that Farr likens to a high-temperature ceramic, in the sense that the crystalline part of it is stored very near to the melting point of ice. “Equally, the non-ice phase contains fats,” he says, “so there’s all sorts of emulsion physics and surface science to take into consideration.”

Ice cream also has polymers in the mix, so theoretical modelling needs to incorporate the complex physics of polymer–polymer phase separation as well as polymer flow, or “rheology”, which contributes to the product’s texture and material properties. “Air is another significant component of ice cream,” adds Farr, “which means it’s a foam as well as an emulsion.”

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As well as trying to understand how all these subcomponents interact, there’s also the thorny issue of storage. After it’s produced, ice cream is typically kept at low temperatures of about –25 °C – first in the factory, then in transit and finally in a supermarket freezer. But once that tub of salted-caramel or mint choc chip reaches a consumer’s home, it’s likely to be popped in the ice compartment of a fridge freezer at a much milder –6 or –7 °C.

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Manufacturers therefore need to control how those temperature transitions affect the recrystallization of ice. This unwanted outcome can lead to phenomena like “sintering” (which makes a harder product) and “ripening” (which can lead to big ice crystals that can be detected in the mouth and detract from the creamy texture).

“Basically, the whole panoply of soft-matter physics comes into play across the production, transport and storage of ice cream,” says Farr. “Figuring out what sort of materials systems will lead to better storage stability or a more consistent product texture are non-trivial questions given that the global market for ice cream is worth in excess of €100bn annually.”

A shot of coffee?

After almost 20 years working at Unilever, in 2017 Farr took up a role as coffee science expert at JDE Peet’s, the Dutch multinational coffee and tea company. Switching from the chilly depths of ice cream science to the dark arts of coffee production and brewing might seem like a steep career phase change, but the physics of the former provides a solid bridge to the latter.

The overlap is evident, for example, in how instant coffee gets freeze-dried – a low-temperature dehydration process that manufacturers use to extend the shelf-life of perishable materials and make them easier to transport. In the case of coffee, freeze drying (or lyophilization, as it’s commonly known) also helps to retain flavour and aromas.

If you want to study a parameter space that’s not been explored before, the only way to do that is to simulate the core processes using fundamental physics
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After roasting and grinding the raw coffee beans, manufacturers extract a coffee concentrate using high pressure and water. This extract is then frozen, ground up and placed in a vacuum well below 0 °C. A small amount of heat is applied to sublime the ice away and remove the remaining water from the non-ice phase.

The quality of the resulting freeze-dried instant coffee is better than ordinary instant coffee. However, freeze-drying is also a complex and expensive process, which manufacturers seek to fine-tune by implementing statistical methods to optimize, for example, the amount of energy consumed during production.

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Such approaches involve interpolating the gaps between existing experimental data sets, which is where a physics mind-set comes in. “If you want to study a parameter space that’s not been explored before,” says Farr, “the only way to do that is to simulate the core processes using fundamental physics.”

Beyond the production line, Farr has also sought to make coffee more stable when it’s stored at home. Sustainability is the big driver here: JDE Peet’s has committed to make all its packaging compostable, recyclable or reusable by 2030. “Shelf-life prediction has been a big part of this R&D initiative,” he explains. “The work entails using materials science and the physics of mass transfer to develop next-generation packaging and container systems.”

Line of sight

After eight years unpacking the secrets of coffee physics at JDE Peet’s, Farr was given the option to relocate to the Netherlands in mid-2025 as part of a wider reorganization of the manufacturer’s corporate R&D function. However, he decided to stay put in Oxford and is now deciding between another role in the food manufacturing sector, or moving into a new area of research, such as nuclear energy, or even education.

Cool science “The whole panoply of soft-matter physics comes into play across the production, transport and storage of ice-cream,” says industrial physicist Rob Farr. (Courtesy: London Institute for Mathematical Sciences)

Farr believes he gained a lot from his time at JDE Peet’s. As well as studying a wide range of physics problems, he also benefited from the company’s rigorous approach to R&D, whereby projects are regularly assessed for profitability and quickly killed off if they don’t make the cut. Such prioritization avoids wasted effort and investment, but it also demands agility from staff scientists, who have to build long-term research strategies against a project landscape in constant flux.

A senior scientist needs to be someone who colleagues come to informally to discuss their technical challenges
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To thrive in that setting, Farr says collaboration and an open mind are essential. “A senior scientist needs to be someone who colleagues come to informally to discuss their technical challenges,” he says. “You can then find the scientific question which underpins seemingly disparate problems and work with colleagues to deliver commercially useful solutions.” For Farr, it’s a self-reinforcing dynamic. “As more people come to you, the more helpful you become – and I love that way of working.”

What Farr calls “line-of-sight” is another unique feature of industrial R&D in food materials. “Maybe you’re only building one span of a really long bridge,” he notes, “but when you can see the process end-to-end, as well as your part in in it, that is a fantastic motivator.” Indeed, Farr believes that for physicists who want a job doing something useful, the physics of food materials makes a great career. “There are,” he concludes, “no end of intriguing and challenging research questions.”

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Quantum photonics network passes a scaling-up milestone

Isabelle Dumé — Tue, 06 Jan 2026 09:00:15 +0000

Physicists in the UK have succeeded in routing and teleporting entangled states of light between two four-user quantum networks – an important milestone in the development of scalable quantum communications. Led by Mehul Malik and Natalia Herrera Valencia of Heriot-Watt University in Edinburgh, Scotland, the team achieved this milestone thanks to a new method that uses light-scattering processes in an ordinary optical fibre to program a circuit. This approach, which is radically different from conventional methods based on photonic chips, allows the circuit to function as a programmable entanglement router that can implement several different network configurations on demand.

The team performed the experiments using commercially-available optical fibres, which are multi-mode structures that scatter light via random linear optical processes. In simple terms, Herrera Valencia explains that this means the light tends to ricochet chaotically through the fibres along hundreds of internal pathways. While this effect can scramble entanglement, researchers at the Institut Langevin in Paris, France had previously found that the scrambling can be calculated by analysing how the fibre transmits light. What is more, the light-scattering processes in such a medium can be harnessed to make programmable optical circuits – which is exactly what Malik, Herrera Valencia and colleagues did.

“Top-down” approach

The researchers explain that this “top-down” approach simplifies the circuit’s architecture because it separates the layer where the light is controlled from the layer in which it is mixed. Using waveguides for transporting and manipulating the quantum states of light also reduces optical losses. The result is a reconfigurable multi-port device that can distribute quantum entanglement between many users simultaneously in multiple patterns, switching between different channels (local connections, global connections or both) as required.

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A further benefit is that the channels can be multiplexed, allowing many quantum processors to access the system at the same time. The researchers say this is similar to multiplexing in classical telecommunications networks, which makes it possible to send huge amounts of data through a single optical fibre using different wavelengths of light.

Access to a large number of modes

Although controlling and distributing entangled states of light is key for quantum networks, Malik says it comes with several challenges. One of these is that conventional methods based on photonics chips cannot be scaled up easily. They are also very sensitive to imperfections in how they’re made. In contrast, the waveguide-based approach developed by the Heriot-Watt team “opens up access to a large number of modes, providing significant improvements in terms of achievable circuit size, quality and loss,” Malik tells Physics World, adding that the approach also fits naturally with existing optical fibre infrastructures.

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Gaining control over the complex scattering process inside a waveguide was not easy, though. “The main challenge was the learning curve and understanding how to control quantum states of light inside such a complex medium,” Herrera Valencia recalls. “It took time and iteration, but we now have the precise and reconfigurable control required for reliable entanglement distribution, and even more so for entanglement swapping, which is essential for scalable networks.”

While the Heriot-Watt team used the technique to demonstrate flexible quantum networking, Malik and Herrera Valencia say it might also be used for implementing large-scale photonic circuits. Such circuits could have many applications, ranging from machine learning to quantum computing and networking, they add.

Looking ahead, the researchers, who report their work in Nature Photonics, say they are now aiming to explore larger-scale circuits that can operate on more photons and light modes. “We would also like to take some of our network technology out of the laboratory and into the real world,” says Malik, adding that Herrera Valencia is leading a commercialization effort in that direction.

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Band-aid like wearable sensor continuously monitors foetal movement

No Author — Mon, 05 Jan 2026 14:00:58 +0000

Multimodal monitoring Pressure and strain sensors on a clinical trial volunteer undergoing an ultrasound scan (left). Snapshot image of the ultrasound video recording (right). (Courtesy: Yap et al., Sci. Adv. 11 eady2661)

The ability to continuously monitor and interpret foetal movement patterns in the third trimester of a pregnancy could help detect any potential complications and improve foetal wellbeing. Currently, however, such assessment of foetal movement is performed only periodically, with an ultrasound exam at a hospital or clinic.

A lightweight, easily wearable, adhesive patch-based sensor developed by engineers and obstetricians at Monash University in Australia may change this. The patches, two of which are worn on the abdomen, can detect foetal movements such as kicking, waving, hiccups, breathing, twitching, and head and trunk motion.

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Reduced foetal movement can be associated with potential impairment in the central nervous system and musculoskeletal system, and is a common feature observed in pregnancies that end in foetal death and stillbirth. A foetus compromised in utero may reduce movements as a compensatory strategy to lower oxygen consumption and conserve energy.

To help identify foetuses at risk of complications, the Monash team developed an artificial intelligence (AI)-powered wearable pressure–strain combo sensor system that continuously and accurately detects foetal movement-induced motion in the mother’s abdominal skin. As reported in Science Advances, the “band-aid”-like sensors can discriminate between foetal and non-foetal movement with over 90% accuracy.

The system comprises two soft, thin and flexible patches designed to conform to the abdomen of a pregnant woman. One patch incorporates an octagonal gold nanowire-based strain sensor (the “Octa” sensor), the other is an interdigitated electrode-based pressure sensor.

Pressure and strain combo Photograph of the sensors on a pregnant mother (A). Exploded illustration of the foetal kicks strain sensor (B) and the pressure sensor (C). Dimensions of the strain (D) and pressure (E) sensors. (Courtesy: Yap et al., Sci. Adv. 11 eady2661)

The patches feature a soft polyimide-based flexible printed circuit (FPC) that integrates a thin lithium polymer battery and various integrated circuit chips, including a Bluetooth radiofrequency system for reading the sensor’s electrical resistance, storing data and communicating with a smartphone app. Each patch is encapsulated with kinesiology tape and sticks to the abdomen using a medical double-sided silicone adhesive.

The Octa sensor is attached to a separate FPC connector attached to the primary device, enabling easy replacement after each study. The pressure sensor is mounted on the silicone adhesive, to connect with the interdigitated electrode beneath the primary device. The Octa and pressure sensor patches are lightweight (about 3 g) and compact, measuring 63 x 30 x 4 mm and 62 x 28 x 2 mm, respectively.

Trialling the device

The researchers validated their foetal movement monitoring system via comparison with simultaneous ultrasound exams, examining 59 healthy pregnant women at Monash Health. Each participant had the pressure sensor attached to the area of their abdomen where they felt the most vigorous foetal movements, typically in the lower quadrant, while the strain sensor was attached to the region closest to foetal limbs. An accelerometer placed on the participant’s chest captured non-foetal movement data for signal denoising and training the machine-learning model.

Principal investigator Wenlong Cheng, now at the University of Sydney, and colleagues report that “the wearable strain sensor featured isotropic omnidirectional sensitivity, enabling detection of maternal abdominal [motion] over a large area, whereas the wearable pressure sensor offered high sensitivity with a small domain, advantageous for accurate localized foetal movement detection”.

The researchers note that the pressure sensor demonstrated higher sensitivity to movements directly beneath it compared with motion farther away, while the Octa sensor performed consistently across a wider sensing area. “The combination of both sensor types resulted in a substantial performance enhancement, yielding an overall AUROC [area under the receiver operating characteristic curve] accuracy of 92.18% in binary detection of foetal movement, illustrating the potential of combining diverse sensing modalities to achieve more accurate and reliable monitoring outcomes,” they write.

In a press statement, co-author Fae Marzbanrad explains that the device’s strength lies in a combination of soft sensing materials, intelligent signal processing and AI. “Different foetal movements create distinct strain patterns on the abdominal surface, and these are captured by the two sensors,” she says. “The machine-learning system uses the signals to detect when movement occurs while cancelling maternal movements.”

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The lightweight and flexible device can be worn by pregnant women for long periods without disrupting daily life. “By integrating sensor data with AI, the system automatically captures a wider range of foetal movements than existing wearable concepts while staying compact and comfortable,” Marzbanrad adds.

The next steps towards commercialization of the sensors will include large-scale clinical studies in out-of-hospital settings, to evaluate foetal movements and investigate the relationship between movement patterns and pregnancy complications.

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Unlocking novel radiation beams for cancer treatment with upright patient positioning

No Author — Mon, 05 Jan 2026 12:27:49 +0000

Since the beginning of radiation therapy, almost all treatments have been delivered with the patient lying on a table while the beam rotates around them. But a resurgence in upright patient positioning is changing that paradigm. Novel radiation accelerators such as proton therapy, VHEE, and FLASH therapy are often too large to rotate around the patient, making access limited. By instead rotating the patient, these previously hard-to-access beams could now become mainstream in the future.

Join leading clinicians and experts as they discuss how this shift in patient positioning is enabling exploration of new treatment geometries and supporting the development of advanced future cancer therapies.

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L-R Serdar Charyyev, Eric Deutsch, Bill Loo, Rock Mackie

Novel beams covered and their representative speaker

Serdar Charyyev – Proton Therapy – Clinical Assistant Professor at Stanford University School of Medicine
+Eric Deutsch – VHEE FLASH – Head of Radiotherapy at Gustave Roussy
+Bill Loo – FLASH Photons – Professor of Radiation Oncology at Stanford Medicine
+Rock Mackie – Emeritus Professor at University of Wisconsin and Co-Founder and Chairman of Leo Cancer Care

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Ask me anything: Andrew Lamb – ‘Being flexible and curious matters far more than having everything mapped out from the beginning’

Tushna Commissariat — Mon, 05 Jan 2026 11:00:09 +0000

Be curious As CTO of a quantum tech company, Andrew Lamb values evidence-based decision making and being surrounded by experts. (Courtesy: Delta.g)

What skills do you use every day in your job?

A quantum sensor is a combination of lots of different parts working together in harmony: a sensor head containing the atoms and isolating them from the environment; a laser system to probe the quantum structure and manipulate atomic states; electronics to drive the power and timing of a device; and software to control everything and interpret the data. As the person building, developing and maintaining these devices you need to have expertise across all these areas. In addition to these skills, as the CTO my role also requires me to set the company’s technical priorities, determine the focus of R&D activities and act as the top technical authority in the firm.

In a developing field like quantum metrology, evidence-based decision making is crucial as you critically assess information, disregarding what is irrelevant and making an informed choice – especially when the “right answer” may not be obvious for months or even years. Challenges arise that may never have been solved before, and the best way to do so is to dive deep into the “why and how” something happens. Once the root cause is identified a creative solution then needs to be found; whether it is something brand new, or implementing an approach from an entirely different discipline.

What do you like best and least about your job?

The best thing about my job is the way in which it enables me to grow my knowledge and understanding of a wide variety of fields, while also providing me opportunities for creative problem solving. When you surround yourself with people who are experts in their field, there is no end to the opportunities to learn. Before co-founding Delta.g I was a researcher at the University of Birmingham where I learnt my technical skills. Moving into a start-up, we built a multidisciplinary team to address the operational, regulatory and technical barriers to establish a disruptive product in the marketplace. The diversity created within our company has afforded a greater pool of experts to learn from.

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As the CTO, my role sits at the intersection of the technical and the commercial within the business. That means it is my responsibility to translate commercial milestones into a scientific plan, while also explaining our progress to non-experts. This can be challenging and quite stressful at times – particularly when I need to describe our scientific achievements in a way that truly reflects our advances, while still being accessible.

What do you know today that you wish you knew when you were starting out in your career?

For a long time, I didn’t know what direction I wanted to take, and I used to worry that the lack of a clear purpose would hold me back. Today I know that it doesn’t. Instead of fixating on finding a perfect path early on, it’s far more valuable to focus on developing skills that open doors. Whether those skills are technical, managerial or commercial, no knowledge is ever wasted. I’m still surprised by how often something I learned as far back as GCSE ends up being useful in my work now.

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I also wish I had understood just how important it is to stay open to new opportunities. Looking back, every pivotal point in my career – switching from civil engineering to a physics degree, choosing certain undergraduate modules, applying for unexpected roles, even co-founding Delta.g – came from being willing to make a shift when an opportunity appeared. Being flexible and curious matters far more than having everything mapped out from the beginning.

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The environmental and climate cost of war

Fri, 02 Jan 2026 11:00:13 +0000

From cutting onions to a LEGO Jodrell Bank, physics has had its fair share of quirky stories this year. Here is our pick of the best, not in any particular order.

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Our blue planet is a Goldilocks world. We’re at just the right distance from the Sun that Earth – like Baby Bear’s porridge – is not too hot or too cold, allowing our planet to be bathed in oceans of liquid water. But further out in our solar system are icy moons that eschew the Goldilocks principle, maintaining oceans and possibly even life far from the Sun.

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This year saw Physics World report on a raft of innovative and exciting developments in the worlds of medical physics and biotech. These included novel cancer therapies using low-temperature plasma or laser ablation, intriguing new devices such as biodegradable bone screws and a pacemaker smaller than a grain of rice, and neural engineering breakthroughs including an ultrathin bioelectric implant that improves movement in rats with spinal cord injuries and a tiny brain sensor that enables thought control of external devices. Here are a few more research highlights that caught my eye.

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New adaptive optics technology boosts the power of gravitational wave detectors

Isabelle Dumé — Mon, 27 Oct 2025 08:00:47 +0000

Future versions of the Laser Interferometer Gravitational Wave Observatory (LIGO) will be able to run at much higher laser powers thanks to a sophisticated new system that compensates for temperature changes in optical components. Known as FROSTI (for FROnt Surface Type Irradiator) and developed by physicists at the University of California Riverside, US, the system will enable next-generation machines to detect gravitational waves emitted when the universe was just 0.1% of its current age, before the first stars had even formed.

Gravitational waves are distortions in spacetime that occur when massive astronomical objects accelerate and collide. When these distortions pass through the four-kilometre-long arms of the two LIGO detectors, they create a tiny difference in the (otherwise identical) distance that light travels between the centre of the observatory and the mirrors located at the end of each arm. The problem is that detecting and studying gravitational waves requires these differences in distance to be measured with an accuracy of 10^-19m, which is 1/10 000^th the size of a proton.

Extending the frequency range

LIGO overcame this barrier 10 years ago when it detected the gravitational waves produced when two black holes located roughly 1.3 billion light–years from Earth merged. Since then, it and two smaller facilities, KAGRA and VIRGO, have observed many other gravitational waves at frequencies ranging from 30–2000 Hz.

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Observing waves at lower and higher frequencies in the gravitational wave spectrum remains challenging, however. At lower frequencies (around 10–30 Hz), the problem stems from vibrational noise in the mirrors. Although these mirrors are hefty objects – each one measures 34 cm across, is 20 cm thick and has a mass of around 40 kg – the incredible precision required to detect gravitational waves at these frequencies means that even the minute amount of energy they absorb from the laser beam is enough to knock them out of whack.

At higher frequencies (150 – 2000 Hz), measurements are instead limited by quantum shot noise. This is caused by the random arrival time of photons at LIGO’s output photodetectors and is a fundamental consequence of the fact that the laser field is quantized.

A novel adaptive optics device

Jonathan Richardson, the physicist who led this latest study, explains that FROSTI is designed to reduce quantum shot noise by allowing the mirrors to cope with much higher levels of laser power. At its heart is a novel adaptive optics device that is designed to precisely reshape the surfaces of LIGO’s main mirrors under laser powers exceeding 1 megawatt (MW), which is nearly five times the power used at LIGO today.

Though its name implies cooling, FROSTI actually uses heat to restore the mirror’s surface to its original shape. It does this by projecting infrared radiation onto test masses in the interferometer to create a custom heat pattern that “smooths out” distortions and so allows for fine-tuned, higher-order corrections.

The single most challenging aspect of FROSTI’s design, and one that Richardson says shaped its entire concept, is the requirement that it cannot introduce even more noise into the LIGO interferometer. “To meet this stringent requirement, we had to use the most intensity-stable radiation source available – that is, an internal blackbody emitter with a long thermal time constant,” he tells Physics World. “Our task, from there, was to develop new non-imaging optics capable of reshaping the blackbody thermal radiation into a complex spatial profile, similar to one that could be created with a laser beam.”

Richardson anticipates that FROSTI will be a critical component for future LIGO upgrades – upgrades that will themselves serve as blueprints for even more sensitive next-generation observatories like the proposed Cosmic Explorer in the US and the Einstein Telescope in Europe. “The current prototype has been tested on a 40-kg LIGO mirror, but the technology is scalable and will eventually be adapted to the 440-kg mirrors envisioned for Cosmic Explorer,” he says.

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Jan Harms, a physicist at Italy’s Gran Sasso Science Institute who was not involved in this work, describes FROSTI as “an ingenious concept to apply higher-order corrections to the mirror profile.” Though it still needs to pass the final test of being integrated into the actual LIGO detectors, Harms notes that “the results from the prototype are very promising”.

Richardson and colleagues are continuing to develop extensions to their technology, building on the successful demonstration of their first prototype. “In the future, beyond the next upgrade of LIGO (A+), the FROSTI radiation will need to be shaped into an even more complex spatial profile to enable the highest levels of laser power (1.5 MW) ultimately targeted,” explains Richardson. “We believe this can be achieved by nesting two or more FROSTI actuators together in a single composite, with each targeting a different radial zone of the test mass surfaces. This will allow us to generate extremely finely-matched optical wavefront corrections.”

The present study is detailed in Optica.

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A SMART approach to treating lung cancers in challenging locations

No Author — Fri, 24 Oct 2025 12:00:33 +0000

Radiation treatment for patients with lung cancer represents a balancing act, particularly if malignant lesions are centrally located near to critical structures. The radiation may destroy the tumour, but vital organs may be seriously damaged as well.

The standard treatment for non-small cell lung cancer (NSCLC) is stereotactic ablative body radiotherapy (SABR), which delivers intense radiation doses in just a few treatment sessions and achieves excellent local control. For ultracentral lung legions, however – defined as having a planning target volume (PTV) that abuts or overlaps the proximal bronchial tree, oesophagus or pulmonary vessels – the high risk of severe radiation toxicity makes SABR highly challenging.

A research team at GenesisCare UK, an independent cancer care provider operating nine treatment centres in the UK, has now demonstrated that stereotactic MR-guided adaptive radiotherapy (SMART)-based SABR may be a safer and more effective option for treating ultracentral metastatic lesions in patients with histologically confirmed NSCLC. They report their findings in Advances in Radiation Oncology.

SMART uses diagnostic-quality MR scans to provide real-time imaging, 3D multiplanar soft-tissue tracking and automated beam control of an advanced linear accelerator. The idea is to use daily online volume adaptation and plan re-optimization to account for any changes in tumour size and position relative to organs-at-risk (OAR). Real-time imaging enables treatment in breath-hold with gated beam delivery (automatically pausing delivery if the target moves outside a defined boundary), eliminating the need for an internal target volume and enabling smaller PTV margins.

The approach offers potential to enhance treatment precision and target coverage while improving sparing of adjacent organs compared with conventional SABR, first author Elena Moreno-Olmedo and colleagues contend.

A safer treatment option

The team conducted a study to assess the incidence of SABR-related toxicities in patients with histologically confirmed NSCLC undergoing SMART-based SABR. The study included 11 patients with 18 ultracentral lesions, the majority of whom had oligometastatic or olioprogressive disease.

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Patients received five to eight treatment fractions, to a median dose of 40 Gy (ranging from 30 to 60 Gy). The researchers generated fixed-field SABR plans with dosimetric aims including a PTV V_100% (the volume receiving at least 100% of the prescription dose) of 95% or above, a PTV V_95% of 98% or above and a maximum dose of between110% and 140%. PTV coverage was compromised where necessary to meet OAR constraints, with a minimum PTV V_100%of at least 70%.

SABR was performed using a 6 MV 0.35 T MRIdian linac with gated delivery during repeated breath-holds, under continuous MR guidance. Based on daily MRI scans, online plan adaptation was performed for all of the 78 delivered fractions.

The researchers report that both the PTV volume and PTV overlap with ultracentral OARs were reduced in SMART treatments compared with conventional SABR. The median SMART PTV was 10.1 cc, compared with 30.4 cc for the simulated SABR PTV, while the median PTV overlap with OARs was 0.85 cc for SMART (8.4% of the PTV) and 4.7 cc for conventional SABR.

In terms of treatment-related side effects for SMART, the rates of acute and late grade 1–2 toxicities were 54% and 18%, respectively, with no grade 3–5 toxicities observed. This demonstrates the technique’s increased safety compared with non-adaptive SABR treatments, which have exhibited severe rates of toxicity, including treatment-related deaths, in ultracentral tumours.

Two-thirds of patients were alive at the median follow-up point of 28 months, and 93% were free from local progression at 12 months. The median progression-free survival was 5.8 months and median overall survival was 20 months.

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Acknowledging the short follow-up time frame, the researchers note that additional late toxicities may occur. However, they are hopeful that SMART will be considered as a favourable treatment option for patients with ultracentral NSCLC lesions.

“Our analysis demonstrates that hypofractionated SMART with daily online adaptation for ultracentral NSCLC achieved comparable local control to conventional non-adaptive SABR, with a safer toxicity profile,” they write. “These findings support the consideration of SMART as a safer and effective treatment option for this challenging subgroup of thoracic tumours.”

The SUNSET trial

SMART-based SABR radiotherapy remains an emerging cancer treatment that’s not available yet in many cancer treatment centres. Despite the high risk for patients with ultracentral tumours, SABR is the standard treatment for inoperable NSCLC.

The phase 1 clinical trial, Stereotactic radiation therapy for ultracentral NSCLC: a safety and efficacy trial (SUNSET), assessed the use of SBRT for ultracentral tumours in 30 patients with early-stage NSCLC treated at five Canadian cancer centres. In all cases, the PTVs touched or overlapped the proximal bronchial tree, the pulmonary artery, the pulmonary vein or the oesophagus. Led by Meredith Giuliani of the Princess Margaret Cancer Centre, the trial aimed to determine the maximum tolerated radiation dose associated with a less than 30% rate of grade 3–5 toxicity within two years of treatment.

All patients received 60 Gy in eight fractions. Dose was prescribed to deliver a PTV V_100% of 95%, a PTV V_90% of 99% and a maximum dose of no more than 120% of the prescription dose, with OAR constraints prioritized over PTV coverage. All patients had daily cone-beam CT imaging to verify tumour position before treatment.

At a median follow-up of 37 months, two patients (6.7%) experienced dose-limiting grade 3–5 toxicities – an adverse event rate within the prespecified acceptability criteria. The three-year overall survival was 72.5% and the three-year progression-free survival was 66.1%.

In a subsequent dosimetric analysis, the researchers report that they did not identify any relationship between OAR dose and toxicity, within the dose constraints used in the SUNSET trial. They note that 73% of patients could be treated without compromise of the PTV, and where compromise was needed, the mean PTV D₉₅ (the minimum dose delivered to 95% of the PTV) remained high at 52.3 Gy.

As expected, plans that overlapped with central OARs were associated with worse local control, but PTV undercoverage was not. “[These findings suggest] that the approach of reducing PTV coverage to meet OAR constraints does not appear to compromise local control, and that acceptable toxicity rates are achievable using 60 Gy in eight fractions,” the team writes. “In the future, use of MRI or online adaptive SBRT may allow for safer treatment delivery by limiting dose variation with anatomic changes.”

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Spiral catheter optimizes drug delivery to the brain

No Author — Fri, 24 Oct 2025 08:00:28 +0000

Researchers in the United Arab Emirates have designed a new catheter that can deliver drugs to entire regions of the brain. Developed by Batoul Khlaifat and colleagues at New York University Abu Dhabi, the catheter’s helical structure and multiple outflow ports could make it both safer and more effective for treating a wide range of neurological disorders.

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Modern treatments for brain-related conditions including Parkinson’s disease, epilepsy, and tumours often involve implanting microfluidic catheters that deliver controlled doses of drug-infused fluids to highly localized regions of the brain. Today, these implants are made from highly flexible materials that closely mimic the soft tissue of the brain. This makes them far less invasive than previous designs.

However, there is still much room for improvement, as Khlaifat explains. “Catheter design and function have long been limited by the neuroinflammatory response after implantation, as well as the unequal drug distribution across the catheter’s outlets,” she says.

A key challenge with this approach is that each of the brain’s distinct regions has highly irregular shapes, which makes it incredibly difficult to target via single drug doses. Instead, doses must be delivered either through repeated insertions from a single port at the end of a catheter, or through single insertions across multiple co-implanted catheters. Either way, the approach is highly invasive, and runs the risk of further trauma to the brain.

Multiple ports

In their study, Khlaifat’s team explored how many of these problems stem from existing catheter designs. They tend to be simple tubes with single input and output ports at either end. Using fluid dynamics simulations, they started by investigating how drug outflow would change when multiple output ports are positioned along the length of the catheter.

To ensure this outflow is delivered evenly, they carefully adjusted the diameter of each port to account for the change in fluid pressure along the catheter’s length – so that four evenly spaced ports could each deliver roughly one quarter of the total flow. Building on this innovation, the researchers then explored how the shape of the catheter itself could be adjusted to optimize delivery even further.

“We varied the catheter design from a straight catheter to a helix of the same small diameter, allowing for a larger area of drug distribution in the target implantation region with minimal invasiveness,” explains team member Khalil Ramadi. “This helical shape also allows us to resist buckling on insertion, which is a major problem for miniaturized straight catheters.”

Helical catheter

Based on their simulations, the team fabricated a helical catheter the call Strategic Precision Infusion for Regional Administration of Liquid, or SPIRAL. In their first set of experiments, they tested their simulations in controlled lab conditions. They verified their prediction of even outflow rates across the catheter’s outlets.

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“Our helical device was also tested in mouse models alongside its straight counterpart to study its neuroinflammatory response,” Khlaifat says. “There were no significant differences between the two designs.”

Having validated the safety of their approach, the researchers are now hopeful that SPIRAL could pave the way for new and improved methods for targeted drug delivery within the brain. With the ability to target entire regions of the brain with smaller, more controlled doses, this future generation of implanted catheters could ultimately prove to be both safer and more effective than existing designs.

“These catheters could be optimized for each patient through our computational framework to ensure only regions that require dosing are exposed to therapy, all through a single insertion point in the skull,” describes team member Mahmoud Elbeh. “This tailored approach could improve therapies for brain disorders such as epilepsy and glioblastomas.”

The research is described in the Journal of Neural Engineering.

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Performance metrics and benchmarks point the way to practical quantum advantage

No Author — Thu, 23 Oct 2025 15:35:17 +0000

Quantum connections Measurement scientists are seeking to understand and quantify the relative performance of quantum computers from different manufacturers as well as across the myriad platform technologies. (Courtesy: iStock/Bartlomiej Wroblewski)

From quantum utility today to quantum advantage tomorrow: incumbent technology companies – among them Google, Amazon, IBM and Microsoft – and a wave of ambitious start-ups are on a mission to transform quantum computing from applied research endeavour to mainstream commercial opportunity. The end-game: quantum computers that can be deployed at-scale to perform computations significantly faster than classical machines while addressing scientific, industrial and commercial problems beyond the reach of today’s high-performance computing systems.

Meanwhile, as technology translation gathers pace across the quantum supply chain, government laboratories and academic scientists must maintain their focus on the “hard yards” of precompetitive research. That means prioritizing foundational quantum hardware and software technologies, underpinned by theoretical understanding, experimental systems, device design and fabrication – and pushing out along all these R&D pathways simultaneously.

Bringing order to disorder

Equally important is the requirement to understand and quantify the relative performance of quantum computers from different manufacturers as well as across the myriad platform technologies – among them superconducting circuits, trapped ions, neutral atoms as well as photonic and semiconductor processors. A case study in this regard is a broad-scope UK research collaboration that, for the past four years, has been reviewing, collecting and organizing a holistic taxonomy of metrics and benchmarks to evaluate the performance of quantum computers against their classical counterparts as well as the relative performance of competing quantum platforms.

Funded by the National Quantum Computing Centre (NQCC), which is part of the UK National Quantum Technologies Programme (NQTP), and led by scientists at the National Physical Laboratory (NPL), the UK’s National Metrology Institute, the cross-disciplinary consortium has taken on an endeavour that is as sprawling as it is complex. The challenge lies in the diversity of quantum hardware platforms in the mix; also the emergence of two different approaches to quantum computing – one being a gate-based framework for universal quantum computation, the other an analogue approach tailored to outperforming classical computers on specific tasks.

“Given the ambition of this undertaking, we tapped into a deep pool of specialist domain knowledge and expertise provided by university colleagues at Edinburgh, Durham, Warwick and several other centres-of-excellence in quantum,” explains Ivan Rungger, a principal scientist at NPL, professor in computer science at Royal Holloway, University of London, and lead scientist on the quantum benchmarking project. That core group consulted widely within the research community and with quantum technology companies across the nascent supply chain. “The resulting study,” adds Rungger, “positions transparent and objective benchmarking as a critical enabler for trust, comparability and commercial adoption of quantum technologies, aligning closely with NPL’s mission in quantum metrology and standards.”

Not all metrics are equal – or mature

Made to measure NPL’s Institute for Quantum Standards and Technology (above) is the UK’s national metrology institute for quantum science. (Courtesy: NPL)

For context, a number of performance metrics used to benchmark classical computers can also be applied directly to quantum computers, such as the speed of operations, the number of processing units, as well as the probability of errors to occur in the computation. That only goes so far, though, with all manner of dedicated metrics emerging in the past decade to benchmark the performance of quantum computers – ranging from their individual hardware components to entire applications.

Complexity reigns, it seems, and navigating the extensive literature can prove overwhelming, while the levels of maturity for different metrics varies significantly. Objective comparisons aren’t straightforward either – not least because variations of the same metric are commonly deployed; also the data disclosed together with a reported metric value is often not sufficient to reproduce the results.

“Many of the approaches provide similar overall qualitative performance values,” Rungger notes, “but the divergence in the technical implementation makes quantitative comparisons difficult and, by extension, slows progress of the field towards quantum advantage.”

The task then is to rationalize the metrics used to evaluate the performance for a given quantum hardware platform to a minimal yet representative set agreed across manufacturers, algorithm developers and end-users. These benchmarks also need to follow some agreed common approaches to fairly and objectively evaluate quantum computers from different equipment vendors.

With these objectives in mind, Rungger and colleagues conducted a deep-dive review that has yielded a comprehensive collection of metrics and benchmarks to allow holistic comparisons of quantum computers, assessing the quality of hardware components all the way to system-level performance and application-level metrics.

Drill down further and there’s a consistent format for each metric that includes its definition, a description of the methodology, the main assumptions and limitations, and a linked open-source software package implementing the methodology. The software transparently demonstrates the methodology and can also be used in practical, reproducible evaluations of all metrics.

“As research on metrics and benchmarks progresses, our collection of metrics and the associated software for performance evaluation are expected to evolve,” says Rungger. “Ultimately, the repository we have put together will provide a ‘living’ online resource, updated at regular intervals to account for community-driven developments in the field.”

From benchmarking to standards

Innovation being what it is, those developments are well under way. For starters, the importance of objective and relevant performance benchmarks for quantum computers has led several international standards bodies to initiate work on specific areas that are ready for standardization – work that, in turn, will give manufacturers, end-users and investors an informed evaluation of the performance of a range of quantum computing components, subsystems and full-stack platforms.

What’s evident is that the UK’s voice on metrics and benchmarking is already informing the collective conversation around standards development. “The quantum computing community and international standardization bodies are adopting a number of concepts from our approach to benchmarking standards,” notes Deep Lall, a quantum scientist in Rungger’s team at NPL and lead author of the study. “I was invited to present our work to a number of international standardization meetings and scientific workshops, opening up widespread international engagement with our research and discussions with colleagues across the benchmarking community.”

He continues: “We want the UK effort on benchmarking and metrics to shape the broader international effort. The hope is that the collection of metrics we have pulled together, along with the associated open-source software provided to evaluate them, will guide the development of standardized benchmarks for quantum computers and speed up the progress of the field towards practical quantum advantage.”

That’s a view echoed – and amplified – by Cyrus Larijani, NPL’s head of quantum programme. “As we move into the next phase of NPL’s quantum strategy, the importance of evidence-based decision making becomes ever-more critical,” he concludes. “By grounding our strategic choices in robust measurement science and real-world data, we ensure that our innovations not only push the boundaries of quantum technology but also deliver meaningful impact across industry and society.”

The headline take from NQCC

Quantum computing technology has reached the stage where a number of methods for performance characterization are backed by a large body of real-world implementation and use, as well as by theoretical proofs. These mature benchmarking methods will benefit from commonly agreed-upon approaches that are the only way to fairly, unambiguously and objectively benchmark quantum computers from different manufacturers.

“Performance benchmarks are a fundamental enabler of technology innovation in quantum computing,” explains Konstantinos Georgopoulos, who heads up the NQCC’s quantum applications team and is responsible for the centre’s liaison with the NPL benchmarking consortium. “How do we understand performance? How do we compare capabilities? And, of course, what are the metrics that help us to do that? These are the leading questions we addressed through the course of this study.

”If the importance of benchmarking is a given, so too is collaboration and the need to bring research and industry stakeholders together from across the quantum ecosystem. “I think that’s what we achieved here,” says Georgopoulos. “The long list of institutions and experts who contributed their perspectives on quantum computing was crucial to the success of this project. What we’ve ended up with are better metrics, better benchmarks, and a better collective understanding to push forward with technology translation that aligns with end-user requirements across diverse industry settings.”

End note: NPL retains copyright on this article.

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Quantum computing and AI join forces for particle physics

Hamish Johnston — Thu, 23 Oct 2025 13:57:59 +0000

This episode of the Physics World Weekly podcast explores how quantum computing and artificial intelligence can be combined to help physicists search for rare interactions in data from an upgraded Large Hadron Collider.

My guest is Javier Toledo-Marín, and we spoke at the Perimeter Institute in Waterloo, Canada. As well as having an appointment at Perimeter, Toledo-Marín is also associated with the TRIUMF accelerator centre in Vancouver.

Toledo-Marín and colleagues have recently published a paper called “Conditioned quantum-assisted deep generative surrogate for particle–calorimeter interactions”.

This podcast is supported by Delft Circuits.

As gate-based quantum computing continues to scale, Delft Circuits provides the i/o solutions that make it possible.

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Master’s programme takes microelectronics in new directions

No Author — Thu, 23 Oct 2025 08:28:40 +0000

Professor Zhao Jiong, who leads a Master’s programme in microelectronics technology and material, has been recognized for his pioneering research in 2d ferroelectronics (Courtesy: PolyU)

The microelectronics sector is known for its relentless drive for innovation, continually delivering performance and efficiency gains within ever more compact form factors. Anyone aspiring to build a career in this fast-moving field needs not just a thorough grounding in current tools and techniques, but also an understanding of the next-generation materials and structures that will propel future progress.

That’s the premise behind a Master’s programme in microelectronics technology and materials at the Hong Kong Polytechnic University (PolyU). Delivered by the Department for Applied Physics, globally recognized for its pioneering research in technologies such as two-dimensional materials, nanoelectronics and artificial intelligence, the aim is to provide students with both the fundamental knowledge and practical skills they need to kickstart their professional future – whether they choose to pursue further research or to find a job in industry.

“The programme provides students with all the key skills they need to work in microelectronics, such as circuit design, materials processing and failure analysis,” says programme leader Professor Zhao Jiong, who research focuses on 2D ferroelectrics. “But they also have direct access to more than 20 faculty members who are actively investigating novel materials and structures that go beyond silicon-based technologies.”

The course in also unusual in providing a combined focus on electronics engineering and materials science, providing students with a thorough understanding of the underlying semiconductors and device structures as well as their use in mass-produced integrated circuits. That fundamental knowledge is reinforced through regular experimental work, providing the students with hands-on experience of fabricating and testing electronic devices. “Our cleanroom laboratory is equipped with many different instruments for microfabrication, including thin-film deposition, etching and photolithography, as well as advanced characterization tools for understanding their operating mechanisms and evaluating their performance,” adds Zhao.

In a module focusing on thin-film materials, for example, students gain valuable experience from practical sessions that enable them to operate the equipment for different growth techniques, such as sputtering, molecular beam epitaxy, and both physical and chemical vapour deposition. In another module on materials analysis and characterization, the students are tasked with analysing the layered structure of a standard computer chip by making cross-sections that can be studied with a scanning electron microscope.

During the programme students have access to a cleanroom laboratory that gives them hand-on experience of using advanced tools for fabricating and characterizing electronic materials and structures (Courtesy: PolyU)

That practical experience extends to circuit design, with students learning how to use state-of-the-art software tools for configuring, simulating and analysing complex electronic layouts. “Through this experimental work students gain the technical skills they need to design and fabricate integrated circuits, and to optimize their performance and reliability through techniques like failure analysis,” says Professor Dai Jiyan, PolyU Associate Dean of Students, who also teaches the module on thin-film materials. “This hands-on experience helps to prepare them for working in a manufacturing facility or for continuing their studies at the PhD level.”

Also integrated into the teaching programme is the use of artificial intelligence to assist key tasks, such as defect analysis, materials selection and image processing. Indeed, PolyU has established a joint laboratory with Huawei to investigate possible applications of AI tools in electronic design, providing the students with early exposure to emerging computational methods that are likely to shape the future of the microelectronics industry. “One of our key characteristics is that we embed AI into our teaching and laboratory work,” says Dai. “Two of the modules are directly related to AI, while the joint lab with Huawei helps students to experiment with using AI in circuit design.”

Now in its third year, the Master’s programme was designed in collaboration with Hong Kong’s Applied Science and Technology Research Institute (ASTRI), established in 2000 to enhance the competitiveness of the region through the use of advanced technologies. Researchers at PolyU already pursue joint projects with ASTRI in areas like chip design, microfabrication and failure analysis. As part of the programme, these collaborators are often invited to give guest lectures or to guide the laboratory work. “Sometimes they even provide some specialized instruments for the students to use in their experiments,” says Zhao. “We really benefit from this collaboration.”

Once primed with the knowledge and experience from the taught modules, the students have the opportunity to work alongside one of the faculty members on a short research project. They can choose whether to focus on a topic that is relevant to present-day manufacturing, such as materials processing or advanced packaging technologies, or to explore the potential of emerging materials and devices across applications ranging from solar cells and microfluidics to next-generation memories and neuromorphic computing.

“It’s very interesting for the students to get involved in these projects,” says Zhao. “They learn more about the research process, which can make them more confident to take their studies to the next level. All of our faculty members are engaged in important work, and we can guide the students towards a future research field if that’s what they are interested in.”

There are also plenty of progression opportunities for those who are more interested in pursuing a career in industry. As well as providing support and advice through its joint lab in AI, Huawei arranges visits to its manufacturing facilities and offers some internships to interested students. PolyU also organizes visits to Hong Kong’s Science Park, home to multinational companies such as Infineon as well as a large number of start-up companies in the microelectronics sector. Some of these might support a student’s research project, or offer an internship in areas such as circuit design or microfabrication.

The international outlook offered by PolyU has made the Master’s programme particularly appealing to students from mainland China, but Zhao and Dai believe that the forward-looking ethos of the course should make it an appealing option for graduates across Asia and beyond. “Through the programme, the students gain knowledge about all aspects of the microelectronics industry, and how it is likely to evolve in the future,” says Dai. “The knowledge and technical skills gained by the students offer them a competitive edge for building their future career, whether they want to find a job in industry or to continue their research studies.”

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Resonant laser ablation selectively destroys pancreatic tumours

Tami Freeman — Thu, 23 Oct 2025 08:00:47 +0000

Pancreatic ductal adenocarcinoma (PDAC), the most common type of pancreatic cancer, is an aggressive tumour with a poor prognosis. Surgery remains the only potential cure, but is feasible in just 10–15% of cases. A team headed up at Sichuan University in China has now developed a selective laser ablation technique designed to target PDAC while leaving healthy pancreatic tissue intact.

Thermal ablation techniques, such as radiofrequency, microwave or laser ablation, could provide a treatment option for patients with locally advanced PDAC, but existing methods risk damaging surrounding blood vessels and healthy pancreatic tissues. The new approach, described in Optica, uses the molecular fingerprint of pancreatic tumours to enable selective ablation.

The technique exploits the fact that PDAC tissue contains a large amount of collagen compared with healthy pancreatic tissue. Amide-I collagen fibres exhibit a strong absorption peak at 6.1 µm, thus the researchers surmised that tuning the treatment laser to this resonant wavelength could enable efficient tumour ablation with minimal collateral thermal damage. As such, they designed a femtosecond pulsed laser that can deliver 6.1 µm pulses with a power of more than 1 W.

Resonant wavelength Fourier-transform infrared spectra of PDAC (blue) and the laser (red). (Courtesy: Houkun Liang, Sichuan University)

“We developed a mid-infrared femtosecond laser system for the selective tissue ablation experiment,” says team leader Houkun Liang. “The system is tunable in the wavelength range of 5 to 11 µm, aligning with various molecular fingerprint absorption peaks such as amide proteins, cholesteryl ester, hydroxyapatite and so on.”

Liang and colleagues first examined the ablation efficiency of three different laser wavelengths on two types of pancreatic cancer cells. Compared with non-resonant wavelengths of 1 and 3 µm, the collagen-resonant 6.1 µm laser was far more effective in killing pancreatic cancer cells, reducing cell viability to ranges of 0.27–0.32 and 0.37–0.38, at 0 and 24 h, respectively.

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The team observed similar results in experiments on ectopic PDAC tumours cultured on the backs of mice. Irradiation at 6.1 µm led to five to 10 times deeper tumour ablation than seen for the non-resonant wavelengths (despite using a laser power of 5 W for 1 µm ablation and just 500 mW for 6.1 and 3 µm), indicating that 6.1 µm is the optimal wavelength for PDAC ablation surgery.

To validate the feasibility and safety of 6.1 µm laser irradiation, the team used the technique to treat PDAC tumours on live mice. Nine days after ablation, the tumour growth rate in treated mice was significantly suppressed, with an average tumour volume of 35.3 mm³. In contrast, tumour volume in a control group of untreated mice reached an average of 292.7 mm³, roughly eight times the size of the ablated tumours. No adverse symptoms were observed following the treatment.

Clinical potential

The researchers also used 6.1 µm laser irradiation to ablate pancreatic tissue samples (including normal tissue and PDAC) from 13 patients undergoing surgical resection. They used a laser power of 1 W and four scanning speeds (0.5, 1, 2 and 3 mm/s) with 10 ablation passes, examining 20 to 40 samples for each parameter.

At the slower scanning speeds, excessive energy accumulation resulted in comparable ablation depths. At speeds of 2 or 3 mm/s, however, the average ablation depths in PDAC samples were 2.30 and 2.57 times greater than in normal pancreatic tissue, respectively, demonstrating the sought-after selective ablation. At 3 mm/s, for example, the ablation depth in tumour was 1659.09±405.97 µm, compared with 702.5±298.32 µm in normal pancreas.

The findings show that by carefully controlling the laser power, scanning speed and number of passes, near-complete ablation of PDACs can be achieved, with minimal damage to surrounding healthy tissues.

To further investigate the clinical potential of this technique, the researchers developed an anti-resonant hollow-core fibre (AR-HCF) that can deliver high-power 6.1 µm laser pulses deep inside the human body. The fibre has a core diameter of approximately 113 µm and low bending losses at radii under 10 cm. The researchers used the AR-HCF to perform 6.1 µm laser ablation of PDAC and normal pancreas samples. The ablation depth in PDAC was greater than in normal pancreas, confirming the selective ablation properties.

“We are working together with a company to make a medical-grade fibre system to deliver the mid-infrared femtosecond laser. It consists of AR-HCF to transmit mid-infrared femtosecond pulses, a puncture needle and a fibre lens to focus the light and prevent liquid tissue getting into the fibre,” explains Liang. “We are also making efforts to integrate an imaging unit into the fibre delivery system, which will enable real-time monitoring and precise surgical guidance.”

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Next, the researchers aim to further optimize the laser parameters and delivery systems to improve ablation efficiency and stability. They also plan to explore the applicability of selective laser ablation to other tumour types with distinct molecular signatures, and to conduct larger-scale animal studies to verify long-term safety and therapeutic outcomes.

“Before this technology can be used for clinical applications, highly comprehensive biological safety assessments are necessary,” Liang emphasizes. “Designing well-structured clinical trials to assess efficacy and risks, as well as navigating regulatory and ethical approvals, will be critical steps toward translation. There is a long way to go.”

The post Resonant laser ablation selectively destroys pancreatic tumours appeared first on Physics World.

Doorway states spotted in graphene-based materials

Hamish Johnston — Wed, 22 Oct 2025 13:51:53 +0000

Low-energy electrons escape from some materials via distinct “doorway” states, according to a study done by physicists at Austria’s Vienna Institute of Technology. The team studied graphene-based materials and found that the nature of the doorway states depended on the number of graphene layers in the sample.

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Low-energy electron (LEE) emission from solids is used across a range of materials analysis and processing applications including scanning electron microscopy and electron-beam induced deposition. However, the precise physics of the emission process is not well understood.

Electrons are ejected from a material when a beam of electrons is fired at its surface. Some of these incident electrons will impart energy to electrons residing in the material, causing some resident electrons to be emitted from the surface. In the simplest model, the minimum energy needed for this LEE emission is the electron binding energy of the material.

Frog in a box

In this new study, however, researchers have shown that exceeding the binding energy is not enough for LEE emission from graphene-based materials. Not only does the electron need this minimum energy, it must also be in a specific doorway state or it is unlikely to escape. The team compare this phenomenon to the predicament of a frog in a cardboard box with a window. Not only must the frog hop a certain height to escape the box, it must also begin its hop from a position that will result in it travelling through the hole (see figure).

For most materials, the energy spectrum of LEE electrons is featureless. However, it was known that graphite’s spectrum has an “X state” at about 3.3 eV, where emission is enhanced. This state could be related to doorway states.

To search for doorway states, the Vienna team studied LEE emission from graphite as well as from single-layer and bi-layer graphene. Graphene is a sheet of carbon just one atom thick. Sheets can stick together via the relatively weak Van der Waals force to create multilayer graphene – and ultimately graphite, which comprises a large number of layers.

Because electrons are mostly confined within the graphene layers, the electronic states of single-layer, bi-layer and multi-layer graphene are broadly similar. As a result, it was expected that these materials would have similar LEE emission spectra . However, the Vienna team found a surprising difference.

Emission and reflection

The team made their discovery by firing a beam of relatively low energy electrons (173 eV) incident at 60° to the surface of single-layer and bi-layer graphene as well as graphite. The scattered electrons are then detected at the same angle of reflection. Meanwhile, a second detector is pointed normal to the surface to capture any emitted electrons. In quantum mechanics electrons are indistinguishable, so the modifiers scattered and emitted are illustrative, rather than precise.

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The team looked for coincident signals in both detectors and plotted their results as a function of energy in 2D “heat maps”. These plots revealed that bi-layer graphene and graphite each had doorway states – but at different energies. However, single-layer graphene did not appear to have any doorway states. By combining experiments with calculations, the team showed that doorway states emerge above a certain number of layers. As a result the researchers showed that graphite’s X state can be attributed in part to a doorway state that appears at about five layers of graphene.

“For the first time, we’ve shown that the shape of the electron spectrum depends not only on the material itself, but crucially on whether and where such resonant doorway states exist,” explains Anna Niggas at the Vienna Institute of Technology.

As well as providing important insights in how the electronic properties of graphene morph into the properties of graphite, the team says that their research could also shed light on the properties of other layered materials.

The research is described in Physical Review Letters.

The post Doorway states spotted in graphene-based materials appeared first on Physics World.

NASA’s Jet Propulsion Lab lays off a further 10% of staff

No Author — Wed, 22 Oct 2025 12:02:05 +0000

NASA’s Jet Propulsion Laboratory (JPL) is to lay off some 550 employees as part of a restructuring that began in July. The action affects about 11% of JPL’s employees and represents the lab’s third downsizing in the past 20 months. When the layoffs are complete by the end of the year, the lab will have roughly 4500 employees, down from about 6500 at the start of 2024. A further 4000 employees have already left NASA during the past six months via sacking, retirement or voluntary buyouts.

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Managed by the California Institute of Technology in Pasadena, JPL oversees scientific missions such as the Psyche asteroid probe, the Europa Clipper and the Perseverance rover on Mars. The lab also operates the Deep Space Network that keeps Earth in communication with unmanned space missions. JPL bosses already laid off about 530 staff – and 140 contractors – in February last year followed by another 325 people in November 2024.

JPL director Dave Gallagher insists, however, that the new layoffs are not related to the current US government shutdown that began on 1 October. “[They are] essential to securing JPL’s future by creating a leaner infrastructure, focusing on our core technical capabilities, maintaining fiscal discipline, and positioning us to compete in the evolving space ecosystem,” he says in a message to employees.

Judy Chu, Democratic Congresswoman for the constituency that includes JPL, is less optimistic. “Every layoff devastates the highly skilled and uniquely talented workforce that has made these accomplishments possible,” she says. “Together with last year’s layoffs, this will result in an untold loss of scientific knowledge and expertise that threatens the very future of American leadership in space exploration and scientific discovery.”

John Logsdon, professor emeritus at George Washington University and founder of the university’s Space Policy Institute, says that the cuts are a direct result of the Trump administration’s approach to science and technology. “The administration gives low priority to robotic science and exploration, and has made draconic cuts to the science budget; that budget supports JPL’s work,” he told Physics World. “With these cuts, there is not enough money to support a JPL workforce sized for more ambitious activities. Ergo, staff cuts.”

The post NASA’s Jet Propulsion Lab lays off a further 10% of staff appeared first on Physics World.

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