In materials science, the yield point represents a critical threshold where a material transitions from elastic to plastic deformation. Below this point, materials like glasses can return to their original shape after stress is removed. Beyond it, however, the deformation becomes permanent, reflecting irreversible changes in the material’s internal structure. Understanding this transition is essential for designing materials that can withstand mechanical stress without failure, an important consideration in fields such as civil engineering, aerospace and electronics.

Despite its importance, the yield point in amorphous materials like glasses has remained difficult to study due to the challenges in precisely controlling and measuring the stress and strain required to trigger it. Traditional mechanical testing methods often lack the resolution needed to observe the subtle atomic-scale changes that occur during yielding.

In this study, the authors present a novel approach using X-ray irradiation to induce yielding in germanium-selenium glasses. This method allows for fine-tuned control over the elasto-plastic transition, enabling the researchers to systematically investigate the onset of plastic deformation. By combining experimental techniques with theoretical modelling, they characterize both the thermodynamic behaviour and the atomic-level structural and dynamical responses of the glasses during and after irradiation.

One of the key findings is that glasses processed through this method become stable against further irradiation, an effect that could be highly beneficial in environments with high radiation exposure, such as space missions or nuclear facilities. This work not only provides new insights into the fundamental physics of yielding in disordered materials but also opens up potential pathways for engineering radiation-resistant glassy materials.

Do you want to learn more about this topic?

Theories of glass formation and the glass transition by J S Langer (2014)

The post Probing the yield point in glasses via controlled irradiation appeared first on Physics World.

Quantum repeaters are essential components of quantum networks, enabling long-distance entanglement distribution by temporarily storing quantum states. This temporary storage, facilitated by quantum memory, allows synchronization with other network operations and the implementation of error correction protocols, marking a significant advancement over classical repeaters, which merely amplify and retransmit signals. 

Unlike classical systems, quantum repeaters mitigate photon loss, a major source of error in quantum communication. However, widely known quantum repeater designs often suffer from limitations such as the need for high phase stability and an inability to generate strongly entangled states. 

In this work, the authors propose a novel protocol based on post-matching, a technique originally developed in quantum cryptography to verify and secure transmitted information. Their theoretical framework offers new insights into both quantum communication and cryptographic systems, contributing to the advancement of quantum information theory and technology. 

Do you want to learn more about this topic?

Explore our Focus on Quantum Entanglement: State of the Art and Open Questions

The post Quantum memory meets cryptography appeared first on Physics World.

Nonlinearity refers to behaviour that deviates from a simple, proportional relationship and cannot be accurately described by linear equations. This concept is fundamental to understanding complex systems across various scientific disciplines, including meteorology, epidemiology, chemistry, and quantum mechanics. 

In the field of quantum optics, achieving nonlinearity at the single-photon level is essential for the development of advanced quantum information protocols. Such nonlinearity enables more precise control over information transmission, facilitates faster and more scalable quantum networks, and enhances the security of quantum communication. 

Rydberg atoms, which are atoms in highly excited states, exhibit strong long-range interactions. These interactions, particularly the Rydberg blockade effect, make them promising candidates for inducing strong nonlinear interactions between photons. However, a key challenge lies in achieving this nonlinearity in a controllable and efficient manner, rather than relying on probabilistic or inefficient methods. 

In this work, the authors introduce a novel approach for precisely engineering Rydberg states to enable continuous tuning of single-photon nonlinearity. This tunability represents a significant advancement, with potential applications spanning fundamental physics and the development of next-generation quantum technologies. 

Do you want to learn more about this topic?

Probing quantum correlations in many-body systems: a review of scalable methods by Irénée Frérot, Matteo Fadel and Maciej Lewenstein (2023)

The post Shaping light with engineered Rydberg states appeared first on Physics World.

Supersymmetry is a theoretical framework in which every fermion and boson has a corresponding partner particle, known as a superpartner. These superpartners share the same energy spectrum but differ in their spin properties. The transformations between these particles are governed by mathematical operators called supercharges. Although superpartners have not yet been observed experimentally, their discovery would have significant implications for fundamental physics. 

Twisted bilayer materials, such as graphene and transition metal dichalcogenides, have attracted attention for their unusual electronic and topological properties. In this study, the authors investigate how supersymmetry manifests in these systems by analysing different energy modes associated with twisted bilayers. 

They find that superpartners can exhibit both trivial and nontrivial topological energy bands. Furthermore, they demonstrate that supersymmetry can spontaneously break due to interactions between charged particles, known as Coulomb interactions. 

This research provides new insights into the interplay between topology, symmetry, and interactions in low-dimensional materials, and opens up new possibilities for exploring supersymmetry in condensed matter systems. 

Do you want to learn more about this topic?

Desperately seeking supersymmetry (SUSY) by Stuart Raby (2004)

The post Exploring supersymmetry through twisted bilayer materials appeared first on Physics World.

The Lipkin-Meshkov-Glick model is a theoretical framework used to describe systems of many interacting spins in an external magnetic field. It has been widely applied to study quantum phase transitions, entanglement, and collective spin behaviour. When extended to two modes, the model allows particles to tunnel between two degenerate energy levels, offering insights into quantum systems with multiple states. 

In this study, the authors propose a chiral two mode version of the model using a pair of surface acoustic wave cavities. The chirality in the system preserves the separation between the two modes and prevents them from mixing. By applying specially designed chiral optical drives, the researchers are able to simulate long range asymmetric spin interactions.

This setup enables the simulation of complex quantum phenomena such as time crystal behaviour and ion trap like interactions, without the need for traditional trapping techniques. The work presents a novel approach to engineering and exploring chiral quantum systems using acoustic hybrid platforms.  

Do you want to learn more about this topic?

Time crystals: a review by Krzysztof Sacha and Jakub Zakrzewski (2018)

The post Chiral spin dynamics and time crystals in acoustic systems appeared first on Physics World.

Developing a unified theory for liquid behaviour has long been a challenge due to the complex interactions between particles and the constantly changing dynamic disorder within liquids. Current approaches rely on empirical equations of state derived from experiments, which are often specific to individual systems and cannot be easily transferred to others. Compared to the well-established thermodynamic models for solids and gases, our understanding of liquids remains significantly underdeveloped. 

In this study, the authors take a foundational step toward creating a general equation of state for liquids based on phonon theory. If successful, such a model could have wide-ranging applications in planetary science, industrial processes, chemical engineering, and condensed matter physics. 

The authors provide a detailed explanation of how they approached this complex problem and apply their theoretical framework to experimental data for argon and nitrogen. The results show strong agreement, suggesting that the model has the potential for broad applicability. 

This work represents a significant advance in the theoretical understanding of liquids and opens the door to a more unified and transferable approach to liquid thermodynamics. 

Do you want to learn more about this topic?

Collective modes and thermodynamics of the liquid state by K Trachenko and V V Brazhkin (2015)

The post Toward a unified equation of state for liquids based on phonon theory appeared first on Physics World.

One of the key challenges in building scalable quantum computers is managing noise during operations in order to improve accuracy. Decoherence, which arises from systematic errors and environmental interactions, disrupts quantum information and limits performance. 

Several strategies exist to reduce decoherence. One approach is dynamical decoupling, which averages out noise through carefully timed control pulses. Another is quantum error correction, which detects and corrects faults in a quantum computation. In this study, the authors explore a third approach by leveraging the symmetry of quantum systems to create decoherence-free subspaces. These subspaces isolate quantum information from environmental noise. 

The authors investigate how these decoherence-free subspaces can be integrated with existing error protection techniques. They construct a logical qubit within a decoherence-free subspace using a specially designed pulse sequence. When combined with dynamical decoupling, this method improves the fidelity of quantum states by up to 23% compared to physical qubits. 

This research presents a practical and effective way to incorporate decoherence-free subspaces into quantum error management, offering a promising path toward more reliable quantum computing. 

Do you want to learn more about this topic?

Quantum algorithms for scientific computing by R Au-Yeung, B Camino, O Rathore and V Kendon (2024)

The post Decoherence-free subspaces for scalable quantum error management appeared first on Physics World.

Time crystals are an intriguing state of matter in which a system exhibits periodic motion even in its lowest energy state. This challenges conventional expectations in physics. These systems arise when time translation symmetry is broken, a principle that normally ensures physical laws remain unchanged over time. 

Unlike ordinary systems, time crystals can exhibit persistent oscillations without absorbing net energy over time. This makes them a subject of great interest in condensed matter physics and a promising candidate for future technologies such as quantum computing, sensing, superconductivity, and energy storage. 

Time crystals can be classified as either discrete or continuous. An external periodic force drives discrete time crystals, while continuous time crystals emerge from the collective and self-sustained oscillations of particles. 

In this study, the authors demonstrate a method for converting a continuous time crystal into a discrete one using a process known as subharmonic injection locking. This technique synchronizes the system’s oscillations with a fraction of the driving frequency. It enables the first observation of a transition between continuous and discrete time crystal states in a system that is not in equilibrium. 

This research provides new insights into the behaviour of time crystals and introduces a powerful approach for controlling and manipulating these unusual phases of matter. 

Do you want to learn more about this topic?

Time crystals: a review by Krzysztof Sacha and Jakub Zakrzewski (2018)

The post Manipulating time crystals between continuous and discrete states appeared first on Physics World.

A strange metal is a type of material that exhibits unusual electrical properties, challenging our conventional understanding of how metals conduct electricity.

In these metals, electrons lose their individual identities, acting collectively in a soup, in which all particles are connected through quantum entanglement. 

Prof. Chung, National Yang Ming Chiao Tung University

Many so-called high temperature superconductors, such as doped cuprates, transition from their superconducting state to a strange metal state as they increase in temperature beyond a critical point. (Note that ‘high’ in this context means above −196.2 °C, the boiling point of liquid nitrogen!)

It has long been thought that revealing the mystery of the strange metal state is the key to understanding the mechanism for high-temperature conductivity. This could lead to understanding what would be required to make a truly room temperature superconductor.

In this new paper, the researchers used a cutting-edge theoretical framework to provide a microscopic description of the strange metal state, focusing on how local charge fluctuations near a critical transition, play a key role.

Their theoretical predictions for quantities such as the specific heat coefficient and the single-particle spectral function in the strange metal state agree well with experimental observations.

This work therefore brings us much closer to understanding how superconductivity emerges from the strange metal state in the cuprates – an open problem in condensed matter physics since the 1990s.

The post How does a strange metal become a room temperature superconductor? appeared first on Physics World.

Most complex carbon molecules – such as those necessary for life – actually exist in two forms. The normal one and its mirror image. The left-handed version and the right-handed version.

Despite containing the same atoms, these two molecules usually have vastly different properties. For example, one might be used as a therapeutic drug, while the other could be inactive or even harmful.

Separating them is therefore very important for several reasons, particularly in the fields of chemistry, biology, and medicine. However, due to the lack of differences in the physical properties of the two molecules, this is usually quite difficult.

When any molecule is exposed to light, its quantum energy levels are split apart because of the interaction.

In this paper, the team found that when this light is circularly polarised, the splitting is different for the two mirrored molecules. They also went on to find that this effect led to different photochemical reactions for each molecule, further providing ways to distinguish them.

These effects could then be used as new methods for separating these mirrored molecules in medicine and beyond.

 

The post What’s the difference between a left-handed molecule and a right-handed one? appeared first on Physics World.

Ever since graphene was first studied in the 2000s, scientists have been interested 2D materials because of their new and interesting electrical and optical properties as well as their potential applications in superconductivity, magnetism and next generation electronics.

In recent years, a new family of these materials has emerged, with a strange new feature: correlated flat bands. Electrons in these bands have the same energy regardless of their movement or position within the material.

In this new work, the researchers used cutting edge theory and computer simulation techniques to understand these types of materials with and predict their properties. In particular, they focused on the interplay between smectic order and topological order.

The term smectic is used when talking about liquid crystals (that’s the same liquid crystal that you find in an LCD TV) . The word just means a state in which the particles are oriented in parallel and arranged in well-defined planes. It’s heavily influenced by the individual particles’ shape structure and charge.

Topological order on other hand is a global type of particle arrangement and is caused by the collective entanglement of all the particles in a system as a whole. It’s very much a quantum phenomenon, and is therefore sometimes unintuitive, strange, and complex.

Usually, these two different types of order are seen to compete with each other, but this study looks at what happens if they exist together.

Based on the results, the team expects several new phase transitions to occur in these systems.

Ultimately, experiments will be required to confirm their predictions. What’s for certain though, is that given how comprehensive this work is, the experimentalists now have a lot of work to do.

The post The different ways of ordering electrons in two dimensional materials. appeared first on Physics World.

Shear-induced structural transitions happen when the structure of a material changes due to the application of force. It’s a phenomenon observed in various systems, including metals like aluminium and iron, molecular crystals such as ice and quartz, and even the Earth’s mantle.

A better understanding of how it works could lead to an improvement in the processing and fabrication of materials with more control on defect formation.

Measuring microscopic processes like this is usually challenging because electron microscopy cannot resolve individual atoms’ motions in bulk solids, and the strong shear force makes things especially difficult.

Here, the researchers used colloidal crystals, allowing them to observe transitions at the single-particle level. As a soft material (one that can easily be deformed), colloid crystals are particularly well-suited for this type of study.

They found that under certain conditions, a liquid layer formed around the growing new crystal structure. This phenomenon is known as “virtual melting” because it occurs well below the effective melting temperature. This liquid layer facilitates the transition by reducing the strain energy at the interface between the old and new crystal structures.

Virtual melting has been proposed in theory and simulation, but had never been directly observed in experiments before. The team’s results not only represent the first experimental observation of this process but also help us to better understand under what circumstances it takes place.

The study has potential applications across various fields, including metallurgy, materials science, and geophysics. The concept of virtual melting could also provide new a new way of thinking about stress relaxation and phase transitions in other systems.

The post Virtual melting accompanies shear-induced crystal transitions appeared first on Physics World.

Protons and neutrons in atomic nuclei are themselves made up of fundamental particles known as quarks. These quarks are held together by the strong interaction via force carriers called gluons.

When heavy atomic nuclei collide at high energies close to the speed of light, these constituent particles can break free from each other. The resulting substance, called a quark–gluon plasma, exhibits collective flowlike behaviour much like an everyday liquid.  Unlike a normal viscous liquid however, these near-perfect fluids lose very little energy as they flow.

Researchers are very interested quark–gluon plasmas because they filled the entire Universe just after the Big Bang before matter as we know it was created.

The CMS Collaboration of scientists at CERN routinely create this state of matter for a very brief moment by colliding large nuclei with each other.  In this paper, the researchers used sound waves as a way of understanding the plasma’s fundamental properties.

Sound is a longitudinal wave that produces compressions and rarefactions of matter in the same direction as its movement. The speed of these waves depends on the medium’s properties, such as its density and viscosity. It can, therefore, be used as a probe of the medium.

The team were able to show that the speed of sound in their quark–gluon plasma was nearly half the speed of light – a measurement they made with record precision compared to previous studies.

The results will help test our theories of the fundamental forces that hold matter together, allowing us to better understand matter in the very early Universe as well as future results at particle colliders.

The post Measuring the speed of sound in quark–gluon plasmas at CERN appeared first on Physics World.

Historically, the majority of studies in condensed matter physics have focused on Hermitian systems – closed systems that conserve energy. However, in reality, dissipative processes or non-equilibrium dynamics are commonly present and so real-world systems are anything but Hermitian.

Recently however people have begun to study non-Hermitian systems in detail and have found a range of interesting topological properties. The term topology was originally used to refer to a branch of mathematics describing geometric objects. Here, however, it means the study of the electron band structure in solids, as well as periodic motion more generally.

Topological arguments are often used to determine universal material properties such as conductivity or magnetic susceptibility. For example, topological insulators are insulating in the bulk but have conducting surface or edge states and can be used in a range of applications, such as quantum computing.

Previous work on non-Hermitian band topology has been restricted to one system at a time, or one property at a time. There’s been no way to link between materials or scenarios and no generalisation.

A research team formed of scientists from the Freie Universität Berlin, the Perimeter Institute, and Stockholm University have now brought everything together by using symmetry arguments to build a general, comprehensive theoretical framework for these exciting new systems.

Predictions made by the authors’ analysis will lead to a better understanding of condensed matter physics and hopefully to new developments in a range of fields including optics, acoustics, and electronics.

The post How to make new materials by predicting their universal electronic structure appeared first on Physics World.

A molecular machine is an assembly of molecular components that produces mechanical movements in response to specific stimuli, similar to everyday objects like hinges and switches.

The power of what can be accomplished with these machines in biology is huge. They are responsible for everything from muscle contraction to DNA replication.

Attaining the same precise control over molecular motion with artificial molecular machines, is currently an active area of research.

Researchers from the August Chełkowski Institute of Physics have been studying one component of these machines – rotary molecular motors. As the name suggests, these machines convert chemical or electrochemical energy into mechanical work by rotating one part relative to another.

The team built their motors out of phenylene molecules within a solid crystal and studied them with a technique called broadband dielectric spectroscopy.

This measures how a material responds to a varying electrical field.  In addition to imaging rotational motion, it can detect interactions between the molecular machine and its environment.

The team found several key markers within their data that reflected the strength of these interactions and therefore how well the molecular rotors were able to rotate. Using these markers will be important in optimising the design of future molecular rotors and brings us one step closer towards artificial molecular machines.

The post How to make a motor the size of a molecule appeared first on Physics World.

New techniques have recently allowed the study of the behaviour of electrons in a similar way to how photons are studied in traditional optics. This emerging area of research – called quantum electron optics – focuses on manipulating and controlling electron waves to create phenomena such as interference and diffraction.

These wavelike electrons are fundamentally quantum in nature. This means that they can emit light in unique ways when shaped and modulated by lasers.

In this work, the team found that the rate of light emission by electrons does not depend on the shape of the electron wave, while the quantum state of the emitted light does.

Essentially, this means that by changing the shape of the electron wave, they can control the characteristics of the light produced. The emitted light exhibits non-classical quantum properties, differing significantly from the light we encounter daily, which follows classical physics rules.

To produce a much stronger photon signal, the researchers also took advantage of superradiance, where multiple electrons emit light in a coordinated manner, resulting in a much stronger emission than the sum of individual emissions. Another purely quantum effect.

The excitement around this research is based on its potential to advance quantum computing and communication by providing new tools for controlling the many quantum states that are required to make them work.

It could also lead to the development of new light sources with special properties, useful in a whole range of scientific and technological applications.

The post How wavelike electrons produce quantum light appeared first on Physics World.

Quantum systems tend to become less “quantum-y” as they interact with their environment. So when developing a mathematical description, it’s usually simpler just to view them as being closed off from their surroundings.

But ‘open’ systems are more realistic and sometimes even more interesting. Open quantum systems can be modelled using the so-called Lindblad equation, which describes the quantum evolution with time as both energy and coherence are lost to the environment.

Scientists from Tsinghua University have expanded the Lindblad equation to track the time evolution in an open system of a quantum property that that has become the hottest topic in condensed-matter physics: topology. Topology has formed the basis of numerous exotic states of matter over the last few decades. Now researchers show that an open system can undergo a topological transition as a result of dissipation, or loss.

The post Tracking the evolution of quantum topology appeared first on Physics World.

Ensuring that different clocks are giving the same time is crucial to enable electronic systems to talk to each other. But what is the cost of this synchronisation at the thermodynamic level?

To answer this question, scientists from the East China Normal University in Shanghai studied two tiny resonating membranes inside an optical cavity. Such optomechanical systems can exhibit quantum properties even on a macroscopic scale, and so they’re an ideal platform for studying ultrasensitive metrology and nonequilibrium thermodynamics. Each of the membranes represented a nanomechanical clock, and the two could be synchronised by increasing their coupling strength by adding more light to the cavity. In this way, the team was able to measure the dependence of the degree of synchronisation on the overall entropy cost.

They hope that this experimental investigation will serve as a starting point to explore synchronisation in navigation-satellite and fibre-optic systems with the aim of improving clock performance.

The post Synchronising two clocks comes at a thermodynamic cost appeared first on Physics World.

The Earth is not a perfect sphere. This makes very precise modelling of our planet’s gravitational field rather tricky. To simplify the maths, scientists can consider a so-called Brillouin sphere: the smallest planet-centred sphere that completely encloses the mass composing the planet. In the case of the Earth, the Brillouin sphere touches the Earth at a single point—the top of Mount Chimborazo in Ecuador. The gravitational field outside the sphere can be accurately simulated by combining a series of simple equations called a spherical harmonic expansion.

But does this still hold true for the field inside the Brillouin sphere, which by definition includes the planet’s surface? Scientists from Ohio State University and the University of Connecticut say “no”. The team presented an analytical and numerical study that demonstrates clearly how and why the spherical harmonic expansion leads to prediction errors.

However, all is not lost. Their ultra-accurate simulations of the gravity field offer guidance toward a new mathematical foundation of gravity modelling. An upgraded simulator, which accounts for density variations within planets, will allow rigorous testing of proposed alternative ways to represent the gravity field beneath the Brillouin sphere.

The post Accounting for planetary density variations helps simulate the gravitational field appeared first on Physics World.

Periodic changes in celestial bodies provide astronomers with a great deal of information about the universe. Sporadic alterations in a star’s brightness could be a signature of it being part of a binary system or indicate the presence of an orbiting planet. And the periodic rotation of objects in the Kuiper Belt tells us about planet formation and the development of our solar system. But these changes are rarely perfectly regular, so astronomers have developed a range of statistical methods to characterize aperiodic observations.

Now, mathematical statisticians from North Carolina State University have compared the robustness of these various methods for the first time. The team investigated the success of four different methods using the same simulated data, and were able to develop a list of recommended usage and limitations that will be essential guidance for all observation astronomers.

The post Periodic changes in celestial bodies give away the galaxy’s secrets appeared first on Physics World.

What would it take to run a cable from the ISS to Earth? Depends how fast you want the Earth to rotate.

Grid operators around the world are under intense pressure to expand and modernize their power networks. The International Energy Authority predicts that demand for electricity will rise by 30% in this decade alone, fuelled by global economic growth and the ongoing drive towards net zero. At the same time, electrical transmission systems must be adapted to handle the intermittent nature of renewable energy sources, as well as the extreme and unpredictable weather conditions that are being triggered by climate change.

High-voltage capacitors play a crucial role in these power networks, balancing the electrical load and managing the flow of current around the grid. For more than 40 years, the standard dielectric for storing energy in these capacitors has been a thin film of a polymer material called biaxially oriented polypropylene (BOPP). However, as network operators upgrade their analogue-based infrastructure with digital technologies such as solid-state transformers and high-frequency switches, BOPP struggles to provide the thermal resilience and reliability that are needed to ensure the stability, scalability and security of the grid.

“We’re trying to bring innovation to an area that hasn’t seen it for a very long time,” says Dr Mike Ponting, Chief Scientific Officer of Peak Nano, a US firm specializing in advanced polymer materials. “Grid operators have been using polypropylene materials for a generation, with no improvement in capability or performance. It’s time to realize we can do better.”

Peak Nano has created a new capacitor film technology that address the needs of the digital power grid, as well as other demanding energy storage applications such as managing the power supply to data centres, charging solutions for electric cars, and next-generation fusion energy technology. The company’s Peak NanoPlex™ materials are fabricated from multiple thin layers of different polymer materials, and can be engineered to deliver enhanced performance for both electrical and optical applications. The capacitor films typically contain polymer layers anywhere between 32 and 156 nm thick, while the optical materials are fabricated with as many as 4000 layers in films thinner than 300 µm.

“When they are combined together in an ordered, layered structure, the long polymer molecules behave and interact with each other in different ways,” explains Ponting. “By putting the right materials together, and controlling the precise arrangement of the molecules within the layers, we can engineer the film properties to achieve the performance characteristics needed for each application.”

In the case of capacitor films, this process enhances BOPP’s properties by interleaving it with another polymer. Such layered films can be optimized to store four times the energy as conventional BOPP while achieving extremely fast charge/discharge rates. Alternatively, they can be engineered to deliver longer lifetimes at operating temperatures some 50–60°C higher than existing materials. Such improved thermal resilience is useful for applications that experience more heat, such as mining and aerospace, and is also becoming an important priority for grid operators as they introduce new transmission technologies that generate more heat.

“We talked to the users of the components to find out what they needed, and then adjusted our formulations to meet those needs,” says Ponting. “Some people wanted smaller capacitors that store a lot of energy and can be cycled really fast, while others wanted an upgraded version of BOPP that is more reliable at higher temperatures.”

The multilayered materials now being produced by Peak Nano emerged from research Ponting was involved in while he was a graduate student at Case Western Reserve University in the 2000s, where Ponting was a graduate student. Plastics containing just a few layers had originally been developed for everyday applications like gift wrap and food packaging, but scientists were starting to explore the novel optical and electronic properties that emerge when the thickness of the polymer layers is reduced to the nanoscale regime.

Small samples of these polymer nanocomposites produced in the lab demonstrated their superior performance, and Peak Nano was formed in 2016 to commercialize the technology and scale up the fabrication process. “There was a lot of iteration and improvement to produce large quantities of the material while still maintaining the precision and repeatability of the nanostructured layers,” says Ponting, who has been developing these multilayered polymer materials and the required processing technology for more than 20 years. “The film properties we want to achieve require the polymer molecules to be well ordered, and it took us a long time to get it right.”

As part of this development process, Peak Nano worked with capacitor manufacturers to create a plug-and-play replacement technology for BOPP that can be used on the same manufacturing systems and capacitor designs as BOPP today. By integrating its specialist layering technology into these existing systems, Peak Nano has been able to leverage established supply chains for materials and equipment rather than needing to develop a bespoke manufacturing process. “That has helped to keep costs down, which means that our layered material is only slightly more expensive than BOPP,” says Ponting.

Ponting also points out that long term, NanoPlex is a more cost-effective option. With improved reliability and resilience, NanoPlex can double or even quadruple the lifetime of a component. “The capacitors don’t need to be replaced as often, which reduces the need for downtime and offsets the slightly higher cost,” he says.

For component manufacturers, meanwhile, the multilayered films can be used in exactly the same way as conventional materials. “Our material can be wound into capacitors using the same process as for polypropylene,” says Ponting. “Our customers don’t need to change their process; they just need to design for higher performance.”

Initial interest in the improved capabilities of NanoPlex came from the defence sector, with Peak Nano benefiting from investment and collaborative research with the US Defense Advanced Research Projects Agency (DARPA) and the Naval Research Laboratory. Optical films produced by the company have been used to fabricate lenses with a graduated refractive index, reducing the size and weight of head-mounted visual equipment while also sharpening the view. Dielectric films with a high breakdown voltage are also a common requirement within the defence community.

The post Nanostructured plastics deliver energy innovation appeared first on Physics World.

Superfluorescence is a collective quantum phenomenon in which many excited particles emit light coherently in a sudden, intense burst. It is usually only observed at cryogenic temperatures, but researchers in the US and France have now determined how and why superfluorescence occurs at room temperature in a lead halide perovskite. The work could help in the development of materials that host exotic coherent quantum states – like superconductivity, superfluidity or superfluorescence – under ambient conditions, they say.

Superfluorescence and other collective quantum phenomena are rapidly destroyed at temperatures higher than cryogenic ones because of thermal vibrations produced in the crystal lattice. In the system studied in this work, the researchers, led by physicist Kenan Gundogdu of North Carolina State University, found that excitons (bound electron–hole pairs) spontaneously form localized, coherence-preserving domains. “These solitons act like quantum islands,” explains Gundogdu. “Excitons inside these islands remain coherent while those outside rapidly dephase.”

The soliton structure acts as a shield, he adds, protecting its content from thermal disturbances – a behaviour that represents a kind of quantum analogue of “soundproofing” – that is, isolation from vibrations. “Here, coherence is maintained not by external cooling but by intrinsic self-organization,” he says.

Intense, time-delayed bursts of coherent emission

The team, which also includes researchers from Duke University, Boston University and the Institut Polytechnique de Paris, began their experiment by exciting lead halide perovskite samples with intense femtosecond laser pulses to generate a dense population of excitons in the material. Under normal conditions, these excitons recombine and emit light incoherently, but at high enough densities, as was the case here, the researchers observed intense, time-delayed bursts of coherent emission, which is a signature of superfluorescence.

When they analysed how the emission evolved over time, the researchers observed that it fluctuated. Surprisingly, these fluctuations were not random, explains Gundogdu, but were modulated by a well-defined frequency, corresponding to a specific lattice vibrational mode. “This suggested that the coherent excitons that emit superfluorescence come from a region in the lattice in which the lattice modes themselves oscillate in synchrony.”

So how can coherent lattice oscillations arise in a thermally disordered environment? The answer involves polarons, says Gundogdu. These are groups of excitons that locally deform the lattice. “Above a critical excitation density, these polarons self-organize into a soliton, which concentrates energy into specific vibrational modes while suppressing others. This process filters out incoherent lattice motion, allowing a stable collective oscillation to emerge.”

The new work, which is detailed in Nature, builds on a previous study in which the researchers had observed superfluorescence in perovskites at room temperature – an unexpected result. They suspected that an intrinsic effect was protecting excitons from dephasing – possibly through a quantum analogue of vibration isolation as mentioned – but the mechanism behind this was unclear.

In this latest experiment, the team determined how polarons can self-organize into soliton states, and revealed an unconventional form of superfluorescence where coherence emerges intrinsically inside solitons. This coherence protection mechanism might be extended to other macroscopic quantum phenomena such as superconductivity and superfluidity.

“These effects are foundational for quantum technologies, yet how coherence survives at high temperatures is still unresolved,” Gundogdu tells Physics World. “Our findings provide a new principle that could help close this knowledge gap and guide the design of more robust, high-temperature quantum systems.”

The post Soliton structure protects superfluorescence appeared first on Physics World.

Light has always played a central role in healthcare, enabling a wide range of tools and techniques for diagnosing and treating disease. Nick Stone from the University of Exeter is a pioneer in this field, working with technologies ranging from laser-based cancer therapies to innovative spectroscopy-based diagnostics. Stone was recently awarded the Institute of Physics’ Rosalind Franklin Medal and Prize for developing novel Raman spectroscopic tools for rapid in vivo cancer diagnosis and monitoring. Physics World’s Tami Freeman spoke with Stone about his latest research.

What is Raman spectroscopy and how does it work?

Think about how we see the sky. It is blue due to elastic (specifically Rayleigh) scattering – when an incident photon scatters off a particle without losing any energy. But in about one in a million events, photons interacting with molecules in the atmosphere will be inelastically scattered. This changes the energy of the photon as some of it is taken by the molecule to make it vibrate.

If you shine laser light on a molecule and cause it to vibrate, the photon that is scattered from that molecule will be shifted in energy by a specific amount relating to the molecule’s vibrational mode. Measuring the wavelength of this inelastically scattered light reveals which molecule it was scattered from. This is Raman spectroscopy.

Because most of the time we’re working at room or body temperatures, most of what we observe is Stokes Raman scattering, in which the laser photons lose energy to the molecules. But if a molecule is already vibrating in an excited state (at higher temperature), it can give up energy and shift the laser photon to a higher energy. This anti-Stokes spectrum is much weaker, but can be very useful – as I’ll come back to later.

How are you using Raman spectroscopy for cancer diagnosis?

A cell in the body is basically a nucleus: one set of molecules, surrounded by the cytoplasm: another set of molecules. These molecules change subtlety depending on the phenotype [set of observable characteristics] of the particular cell. If you have a genetic mutation, which is what drives cancer, the cell tends to change its relative expression of proteins, nucleic acids, glycogen and so on.

We can probe these molecules with light, and therefore determine their molecular composition. Cancer diagnostics involves identifying minute changes between the different compositions. Most of our work has been in tissues, but it can also be done in biofluids such as tears, blood plasma or sweat. You build up a molecular fingerprint of the tissue or cell of interest, and then you can compare those fingerprints to identify the disease.

We tend to perform measurements under a microscope and, because Raman scattering is a relatively weak effect, this requires good optical systems. We’re trying to use a single wavelength of light to probe molecules of interest and look for wavelengths that are shifted from that of the laser illumination. Technology improvements have provided holographic filters that remove the incident laser wavelength readily, and less complex systems that enable rapid measurements.

Raman spectroscopy can classify tissue samples removed in cancer surgery, for example. But can you use it to detect cancer without having to remove tissue from the patient?

Absolutely, we’ve developed probes that fit inside an endoscope for diagnosing oesophageal cancer.

Earlier in my career I worked on photodynamic therapy. We would look inside the oesophagus with an endoscope to find disease, then give the patient a phototoxic drug that would target the diseased cells. Shining light on the drug causes it to generate singlet oxygen that kills the cancer cells. But I realized that the light we were using could also be used for diagnosis.

Currently, to find this invisible disease, you have to take many, many biopsies. But our in vivo probes allow us to measure the molecular composition of the oesophageal lining using Raman spectroscopy, to be and determine where to take biopsies from. Oesophageal cancer has a really bad outcome once it’s diagnosed symptomatically, but if you can find the disease early you can deliver effective treatments. That’s what we’re trying to do.

The very weak Raman signal, however, causes problems. With a microscope, we can use advanced filters to remove the incident laser wavelength. But sending light down an optical fibre generates unwanted signal, and we also need to remove elastically scattered light from the oesophagus. So we had to put a filter on the end of this tiny 2 mm fibre probe. In addition, we don’t want to collect photons that have travelled a long way through the body, so we needed a confocal system. We built a really complex probe, working in collaboration with John Day at the University of Bristol – it took a long time to optimize the optics and the engineering.

Are there options for diagnosing cancer in places that can’t be accessed via an endoscope?

Yes, we have also developed a smart needle probe that’s currently in trials. We are using this to detect lymphomas – the primary cancer in lymph nodes – in the head and neck, under the armpit and in the groin.

If somebody comes forward with lumps in these areas, they usually have a swollen lymph node, which shows that something is wrong. Most often it’s following an infection and the node hasn’t gone back down in size.

This situation usually requires surgical removal of the node to decide whether cancer is present or not. Instead, we can just insert our needle probe and send light in. By examining the scattered light and measuring its fingerprint we can identify if it’s lymphoma. Indeed, we can actually see what type of cancer it is and where it has come from. 

Currently, the prototype probe is quite bulky because we are trying to make it low in cost. It has to have a disposable tip, so we can use a new needle each time, and the filters and optics are all in the handpiece.

Are you working on any other projects at the moment?

As people don’t particularly want a needle stuck in them, we are now trying to understand where the photons travel if you just illuminate the body. Red and near-infrared light travel a long way through the body, so we can use near-infrared light to probe photons that have travelled many, many centimetres.

We are doing a study looking at calcifications in a very early breast cancer called ductal carcinoma in situ (DCIS) – it’s a Cancer Research UK Grand Challenge called DCIS PRECISION, and we are just moving on to the in vivo phase.

Calcifications aren’t necessarily a sign of breast cancer – they are mostly benign; but in patients with DCIS, the composition of the calcifications can show how their condition will progress. Mammographic screening is incredibly good at picking up breast cancer, but it’s also incredibly good at detecting calcifications that are not necessarily breast cancer yet. The problem is how to treat these patients, so our aim is to determine whether the calcifications are completely fine or if they require biopsy.

We are using Raman spectroscopy to understand the composition of these calcifications, which are different in patients who are likely to progress onto invasive disease. We can do this in biopsies under a microscope and are now trying to see whether it works using transillumination, where we send near-infrared light through the breast. We could use this to significantly reduce the number of biopsies, or monitor individuals with DCIS over many years.

Light can also be harnessed to treat disease, for example using photodynamic therapy as you mentioned earlier. Another approach is nanoparticle-based photothermal therapy, how does this work?

This is an area I’m really excited about. Nanoscale gold can enhance Raman signals by many orders of magnitude – it’s called surface-enhanced Raman spectroscopy. We can also “label” these nanoparticles by adding functional molecules to their surfaces. We’ve used unlabelled gold nanoparticles to enhance signals from the body and labelled gold to find things.

During that process, we also realized that we can use gold to provide heat. If you shine light on gold at its resonant frequency, it will heat the gold up and can cause cell death. You could easily blow holes in people with a big enough laser and lots of nanoparticles – but we want to do is more subtle. We’re decorating the tiny gold nanoparticles with a label that will tell us their temperature.

By measuring the ratio between Stokes and anti-Stokes scattering signals (which are enhanced by the gold nanoparticles), we can measure the temperature of the gold when it is in the tumour. Then, using light, we can keep the temperature at a suitable level for treatment to optimize the outcome for the patient.

Ideally, we want to use 100 nm gold particles, but that is not something you can simply excrete through the kidneys. So we’ve spent the last five years trying to create nanoconstructs made from 5 nm gold particles that replicate the properties of 100 nm gold, but can be excreted. We haven’t demonstrated this excretion yet, but that’s the process we’re looking at.

This research is part of a project to combine diagnosis and heat treatment into one nanoparticle system – if the Raman spectra indicate cancer, you could then apply light to the nanoparticle to heat and destroy the tumour cells. Can you tell us more about this?

We’ve just completed a five-year programme called Raman Nanotheranostics. The aim is to label our nanoparticles with appropriate antibodies that will help the nanoparticles target different cancer types. This could provide signals that tell us what is or is not present and help decide how to treat the patient.

We have demonstrated the ability to perform treatments in preclinical models, control the temperature and direct the nanoparticles. We haven’t yet achieved a multiplexed approach with all the labels and antibodies that we want. But this is a key step forward and something we’re going to pursue further.

We are also trying to put labels on the gold that will enable us to measure and monitor treatment outcomes. We can use molecules that change in response to pH, or the reactive oxygen species that are present, or other factors. If you want personalized medicine, you need ways to see how the patient reacts to the treatment, how their immune system responds. There’s a whole range of things that will enable us to go beyond just diagnosis and therapy, to actually monitor the treatment and potentially apply a boost if the gold is still there.

Looking to the future, what do you see as the most promising applications of light within healthcare?

Light has always been used for diagnosis: “you look yellow, you’ve got something wrong with your liver”; “you’ve got blue-tinged lips, you must have oxygen depletion”. But it’s getting more and more advanced. I think what’s most encouraging is our ability to measure molecular changes that potentially reveal future outcomes of patients, and individualization of the patient pathway.

But the real breakthrough is what’s on our wrists. We are all walking around with devices that shine light in us – to measure heartbeat, blood oxygenation and so on. There are already Raman spectrometers that sort of size. They’re not good enough for biological measurements yet, but it doesn’t take much of a technology step forward.

I could one day have a chip implanted in my wrist that could do all the things the gold nanoconstructs might do, and my watch could read it out. And this is just Raman – there are a whole host of approaches, such as photoacoustic imaging or optical coherence tomography. Combining different techniques together could provide greater understanding in a much less invasive way than many traditional medical methods. Light will always play a really important role in healthcare.

• This article is based on a session at the Institute of Physics’ Celebration of Physics in April 2025.

The post Harnessing the power of light for healthcare appeared first on Physics World.

Astronomers in China have observed a pulsar that becomes partially eclipsed by an orbiting companion star every few hours. This type of observation is very rare and could shed new light on how binary star systems evolve.

While most stars in our galaxy exist in pairs, the way these binary systems form and evolve is still little understood. According to current theories, when two stars orbit each other, one of them may expand so much that its atmosphere becomes large enough to encompass the other. During this “envelope” phase, mass can be transferred from one star to the other, causing the stars’ orbit to shrink over a period of around 1000 years. After this, the stars either merge or the envelope is ejected.

In the special case where one star in the pair is a neutron star, the envelope-ejection scenario should, in theory, produce a helium star that has been “stripped” of much of its material and a “recycled” millisecond pulsar – that is, a rapidly spinning neutron star that flashes radio pulses hundreds of times per second. In this type of binary system, the helium star can periodically eclipse the pulsar as it orbits around it, blocking its radio pulses and preventing us from detecting them here on Earth. Only a few examples of such a binary system have ever been observed, however, and all previous ones were in nearby dwarf galaxies called the Magellanic Clouds, rather than our own Milky Way.

A special pulsar

Astronomers led by Jinlin Han from the National Astronomical Observatories of China say they have now identified the first system of this type in the Milky Way. The pulsar in the binary, denoted PSR J1928+1815, had been previously identified using the Five-hundred-meter Aperture Spherical radio Telescope (FAST) during the FAST Galactic Plane Pulsar Snapshot survey. These observations showed that PSR J1928+1815 has a spin period of 10.55 ms, which is relatively short for a pulsar of this type and suggests it had recently sped up by accreting mass from a companion.

The researchers used FAST to observe this suspected binary system at radio frequencies ranging from 1.0 to 1.5 GHz over a period of four and a half years. They fitted the times that the radio pulses arrived at the telescope with a binary orbit model to show that the system has an eccentricity of less than 3 × 10⁻⁵. This suggests that the pulsar and its companion star are in a nearly circular orbit. The diameter of this orbit, Han points out, is smaller than that of our own Sun, and its period – that is, the time it takes the two stars to circle each other – is correspondingly short, at 3.6 hours. For a sixth of this time, the companion star blocks the pulsar’s radio signals.

The team also found that the rate at which this orbital period is changing (the so-called spin period derivative) is unusually high for a millisecond-period pulsar, at 3.63 × 10⁻¹⁸ s s⁻¹ .This shows that energy is rapidly being lost from the system as the pulsar spins down.

“We knew that PSR J1928+1815 was special from November 2021 onwards,” says Han. “Once we’d accumulated data with FAST, one of my students, ZongLin Yang, studied the evolution of such binaries in general and completed the timing calculations from the data we had obtained for this system. His results suggested the existence of the helium star companion and everything then fell into place.”

Short-lived phenomenon

This is the first time a short-life (10⁷ years) binary consisting of a neutron star and a helium star has ever been detected, Han tells Physics World. “It is a product of the common envelope evolution that lasted for only 1000 years and that we couldn’t observe directly,” he says.

“Our new observation is the smoking gun for long-standing binary star evolution theories, such as those that describe how stars exchange mass and shrink their orbits, how the neutron star spins up by accreting matter from its companion and how the shared hydrogen envelope is ejected.”

The system could help astronomers study how neutron stars accrete matter and then cool down, he adds. “The binary detected in this work will evolve to become a system of two compact stars that will eventually merge and become a future source of gravitational waves.”

Full details of the study are reported in Science.

The post Short-lived eclipsing binary pulsar spotted in Milky Way appeared first on Physics World.

As the world celebrates the 2025 International Year of Quantum Science and Technology, it’s natural that we should focus on the exciting applications of quantum physics in computing, communication and cryptography. But quantum physics is also set to have a huge impact on medicine and healthcare. Quantum sensors, in particular, can help us to study the human body and improve medical diagnosis – in fact, several systems are close to being commercialized.

Quantum computers, meanwhile, could one day help us to discover new drugs by providing representations of atomic structures with greater accuracy and by speeding up calculations to identify potential drug reactions. But what other technologies and projects are out there? How can we forge new applications of quantum physics in healthcare and how can we help discover new potential use cases for the technology?

Those are the some of the questions tackled in a recent report, on which this Physics World article is based, published by Innovate UK in October 2024. Entitled Quantum for Life, the report aims to kickstart new collaborations by raising awareness of what quantum physics can do for the healthcare sector. While the report says quite a bit about quantum computing and quantum networking, this article will focus on quantum sensors, which are closer to being deployed.

Sense about sensors

The importance of quantum science to healthcare isn’t new. In fact, when a group of academics and government representatives gathered at Chicheley Hall back in 2013 to hatch plans for the UK’s National Quantum Technologies Programme, healthcare was one of the main applications they identified. The resulting £1bn programme, which co-ordinated the UK’s quantum-research efforts, was recently renewed for another decade and – once again – healthcare is a key part of the remit.

As it happens, most major hospitals already use quantum sensors in the form of magnetic resonance imaging (MRI) machines. Pioneered in the 1970s, these devices manipulate the quantum spin states of hydrogen atoms using magnetic fields and radio waves. By measuring how long those states take to relax, MRI can image soft tissues, such as the brain, and is now a vital part of the modern medicine toolkit.

While an MRI machine measures the quantum properties of atoms, the sensor itself is classical, essentially consisting of electromagnetic coils that detect the magnetic flux produced when atomic spins change direction. More recently, though, we’ve seen a new generation of nanoscale quantum sensors that are sensitive enough to detect magnetic fields emitted by a target biological system. Others, meanwhile, consist of just a single atom and can monitor small changes in the environment.

There are lots of different quantum-based companies and institutions working in the healthcare sector

As the Quantum for Life report shows, there are lots of different quantum-based companies and institutions working in the healthcare sector. There are also many promising types of quantum sensors, which use photons, electrons or spin defects within a material, typically diamond. But ultimately what matters is what quantum sensors can achieve in a medical environment.

Quantum diagnosis

While compiling the report, it became clear that quantum-sensor technologies for healthcare come in five broad categories. The first is what the report labels “lab diagnostics”, in which trained staff use quantum sensors to observe what is going on inside the human body. By monitoring everything from our internal temperature to the composition of cells, the sensors can help to identify diseases such as cancer.

Currently, the only way to definitively diagnose cancer is to take a sample of cells – a biopsy – and examine them under a microscope in a laboratory. Biopsies are often done with visual light but that can damage a sample, making diagnosis tricky. Another option is to use infrared radiation. By monitoring the specific wavelengths the cells absorb, the compounds in a sample can be identified, allowing molecular changes linked with cancer to be tracked.

Unfortunately, it can be hard to differentiate these signals from background noise. What’s more, infrared cameras are much more expensive than those operating in the visible region. One possible solution is being explored by Digistain, a company that was spun out of Imperial College, London, in 2019. It is developing a product called EntangleCam that uses two entangled photons – one infrared and one visible (figure 1).

If the infrared photon is absorbed by, say, a breast cancer cell, that immediately affects the visible photon with which it is entangled. So by measuring the visible light, which can be done with a cheap, efficient detector, you can get information about the infrared photon – and hence the presence of a potential cancer cell (Phys. Rev. 108 032613). The technique could therefore allow cancer to be quickly diagnosed before a tumour has built up, although an oncologist would still be needed to identify the area for the technique to be applied.

Point of care

The second promising application of quantum sensors lies in “point-of-care” diagnostics. We all became familiar with the concept during the COVID-19 pandemic when lateral-flow tests proved to be a vital part of the worldwide response to the virus. The tests could be taken anywhere and were quick, simple, reliable and relatively cheap. Something that had originally been designed to be used in a lab was now available to most people at home.

Quantum technology could let us miniaturize such tests further and make them more accurate, such that they could be used at hospitals, doctor’s surgeries or even at home. At the moment, biological indicators of disease tend to be measured by tagging molecules with fluorescent markers and measuring where, when and how much light they emit. But because some molecules are naturally fluorescent, those measurements have to be processed to eliminate the background noise.

One emerging quantum-based alternative is to characterize biological samples by measuring their tiny magnetic fields. This can be done, for example, using diamond specially engineered with nitrogen-vacancy (NV) defects. Each is made by removing two carbon atoms from the lattice and implanting a nitrogen atom in one of the gaps, leaving a vacancy in the other. Behaving like an atom with discrete energy levels, each defect’s spin state is influenced by the local magnetic field and can be “read out” from the way it fluoresces.

One UK company working in this area is Element Six. It has joined forces with the US-based firm QDTI to make a single-crystal diamond-based device that can quickly identify biomarkers in blood plasma, cerebrospinal fluid and other samples extracted from the body. The device detects magnetic fields produced by specific proteins, which can help identify diseases in their early stages, including various cancers and neurodegenerative conditions like Alzheimer’s. Another firm using single-crystal diamond to detect cancer cells is Germany-based Quantum Total Analysis Systems (QTAS).

Matthew Markham, a physicist who is head of quantum technologies at Element Six, thinks that healthcare has been “a real turning point” for the company. “A few years ago, this work was mostly focused on academic problems,” he says. “But now we are seeing this technology being applied to real-world use cases and that it is transitioning into industry with devices being tested in the field.”

An alternative approach involves using tiny nanometre-sized diamond particles with NV centres, which have the advantage of being highly biocompatible. QT Sense of the Netherlands, for example, is using these nanodiamonds to build nano-MRI scanners that can measure the concentration of molecules that have an intrinsic magnetic field. This equipment has already been used by biomedical researchers to investigate single cells (figure 2).

Australian firm FeBI Technologies, meanwhile, is developing a device that uses nanodiamonds to measure the magnetic properties of ferritin – a protein that stores iron in the body. The company claims its technology is nine orders of magnitude more sensitive than traditional MRI and will allow patients to monitor the amount of iron in their blood using a device that is accurate and cheap.

Wearable healthcare

The third area in which quantum technologies are benefiting healthcare is what’s billed in the Quantum for Life report as “consumer medical monitoring and wearable healthcare”. In other words, we’re talking about devices that allow people to monitor their health in daily life on an ongoing basis. Such technologies are particularly useful for people who have a diagnosed medical condition, such as diabetes or high blood pressure.

NIQS Tech, for example, was spun off from the University of Leeds in 2022 and is developing a highly accurate, non-invasive sensor for measuring glucose levels. Traditional glucose-monitoring devices are painful and invasive because they basically involve sticking a needle in the body. While newer devices use light-based spectroscopic measurements, they tend to be less effective for patients with darker skin tones.

The sensor from NIQS Tech instead uses a doped silica platform, which enables quantum interference effects. When placed in contact with the skin and illuminated with laser light, the device fluoresces, with the lifetime of the fluorescence depending on the amount of glucose in the user’s blood, regardless of skin tone. NIQS has already demonstrated proof of concept with lab-based testing and now wants to shrink the technology to create a wearable device that monitors glucose levels continuously.

Body imaging

The fourth application of quantum tech lies in body scanning, which allows patients to be diagnosed without needing a biopsy. One company leading in this area is Cerca Magnetics, which was spun off from the University of Nottingham. In 2023 it won the inaugural qBIG prize for quantum innovation from the Institute of Physics, which publishes Physics World, for developing wearable optically pumped magnetometers for magnetoencephalography (MEG), which measure magnetic fields generated by neuronal firings in the brain. Its devices can be used to scan patients’ brains in a comfortable seated position and even while they are moving.

Quantum-based scanning techniques could also help diagnose breast cancer, which is usually done by exposing a patient’s breast tissue to low doses of X-rays. The trouble with such mammograms is that all breasts contain a mix of low-density fatty and other, higher-density tissue. The latter creates a “white blizzard” effect against the dark background, making it challenging to differentiate between healthy tissue and potential malignancies.

That’s a particular problem for the roughly 40% of women who have a higher concentration of higher-density tissue. One alternative is to use molecular breast imaging (MBI), which involves imaging the distribution of a radioactive tracer that has been intravenously injected into a patient. This tracer, however, exposes patients to a higher (albeit still safe) dose of radiation than with a mammogram, which means that patients have to be imaged for a long time to get enough signal.

A solution could lie with the UK-based firm Kromek, which is using cadmium zinc telluride (CZT) semiconductors that produce a measurable voltage pulse from just a single gamma-ray photon. As well as being very efficient over a broad range of X-ray and gamma-ray photon energies, CZTs can be integrated onto small chips operating at room temperature. Preliminary results with Kromek’s ultralow-dose and ultrafast detectors show they work with barely one-eighth of the amount of tracer as traditional MBI techniques.

“Our prototypes have shown promising results,” says Alexander Cherlin, who is principal physicist at Kromek. The company is now designing and building a full-size prototype of the camera as part of Innovate UK’s £2.5m “ultralow-dose” MBI project, which runs until the end of 2025. It involves Kromek working with hospitals in Newcastle along with researchers at University College London and the University of Newcastle.

Microscopy matters

The final application of quantum sensors to medicine lies in microscopy, which these days no longer just means visible light but everything from Raman and two-photon microscopy to fluorescence lifetime imaging and multiphoton microscopy. These techniques allow samples to be imaged at different scales and speeds, but they are all reaching various technological limits.

Quantum technologies can help us break the technological limits of microscopy

Quantum technologies can help us break those limits. Researchers at the University of Glasgow, for example, are among those to have used pairs of entangled photons to enhance microscopy through “ghost imaging”. One photon in each pair interacts with a sample, with the image built up by detecting the effect on its entangled counterpart. The technique avoids the noise created when imaging with low levels of light (Sci. Adv. 6 eaay2652).

Researchers at the University of Strathclyde, meanwhile, have used nanodiamonds to get around the problem that dyes added to biological samples eventually stop fluorescing. Known as photobleaching, the effect prevents samples from being studied after a certain time (Roy. Soc. Op. Sci. 6 190589). In the work, samples could be continually imaged and viewed using two-photon excitation microscopy with a 10-fold increase in resolution.

Looking to the future

But despite the great potential of quantum sensors in medicine, there are still big challenges before the technology can be deployed in real, clinical settings. Scalability – making devices reliably, cheaply and in sufficient numbers – is a particular problem. Fortunately, things are moving fast. Even since the Quantum for Life report came out late in 2024, we’ve seen new companies being founded to address these problems.

One such firm is Bristol-based RobQuant, which is developing solid-state semiconductor quantum sensors for non-invasive magnetic scanning of the brain. Such sensors, which can be built with the standard processing techniques used in consumer electronics, allow for scans on different parts of the body. RobQuant claims its sensors are robust and operate at ambient temperatures without requiring any heating or cooling.

Agnethe Seim Olsen, the company’s co-founder and chief technologist, believes that making quantum sensors robust and scalable is vital if they are to be widely adopted in healthcare. She thinks the UK is leading the way in the commercialization of such sensors and will benefit from the latest phase of the country’s quantum hubs. Bringing academia and businesses together, they include the £24m Q-BIOMED biomedical-sensing hub led by University College London and the £27.5m QuSIT hub in imaging and timing led by the University of Birmingham.

Q-BIOMED is, for example, planning to use both single-crystal diamond and nanodiamonds to develop and commercialize sensors that can diagnose and treat diseases such as cancer and Alzheimer’s at much earlier stages of their development. “These healthcare ambitions are not restricted to academia, with many startups around the globe developing diamond-based quantum technology,” says Markham at Element Six.

As with the previous phases of the hubs, allowing for further research encourages start-ups – researchers from the forerunner of the QuSIT hub, for example, set up Cerca Magnetics. The growing maturity of some of these quantum sensors will undoubtedly attract existing medical-technology companies. The next five years will be a busy and exciting time for the burgeoning use of quantum sensors in healthcare.

The post How quantum sensors could improve human health and wellbeing appeared first on Physics World.

The Helgoland 2025 meeting, marking 100 years of quantum mechanics, has featured a lot of mind-bending fundamental physics, quite a bit of which has left me scratching my head.

So it was great to hear a brilliant talk by David Moore of Yale University about some amazing practical experiments using levitated, trapped microspheres as quantum sensors to detect what he calls the “invisible” universe.

If the work sounds familar to you, that’s because Moore’s team won a Physics World Top 10 Breakthrough of the Year award in 2024 for using their technique to detect the alpha decay of individual lead-212 atoms.

Speaking in the Nordseehalle on the island of Helgoland, Moore explained the next stage of the experiment, which could see it detect neutrinos “in a couple of months” at the earliest – and “at least within a year” at the latest.

Of course, physicists have already detected neutrinos, but it’s a complicated business, generally involving huge devices in deep underground locations where background signals are minimized. Yale’s set up is much cheaper, smaller and more convenient, involving no more than a couple of lab benches.

As Moore explained, he and his colleagues first trap silica spheres at low pressure, before removing excess electrons to electrically neutralize them. They then stabilize the spheres’ rotation before cooling them to microkelvin temperatures.

In the work that won the Physics World award last year, the team used samples of radon-220, which decays first into polonium-216 and then lead-212. These nuclei embed theselves in the silica spheres, which recoil when the lead-212 decays by releasing an alpha particle (Phys. Rev. Lett. 133 023602).

Moore’s team is able to measure the tiny recoil by watching how light scatters off the spheres. “We can see the force imparted by a subatomic particle on a heavier object,” he told the audience at Helgoland. “We can see single nuclear decays.”

Now the plan is to extend the experiment to detect neutrinos. These won’t (at least initially) be the neutrinos that stream through the Earth from the Sun or even those from a nuclear reactor.

Instead, the idea will be to embed the spheres with nuclei that undergo beta decay, releasing a much lighter neutrino in the process. Moore says the team will do this within a year and, one day, potentially even use to it spot dark matter.

“We are reaching the quantum measurement regime,” he said. It’s a simple concept, even if the name – “Search for new Interactions in a Microsphere Precision Levitation Experiment” (SIMPLE) – isn’t.

The post Yale researcher says levitated spheres could spot neutrinos ‘within months’ appeared first on Physics World.

According to physics, any blanket can cool you—for a few minutes. But a real cooling blanket is possible with phase-change materials.

The animal world – including some of its ickiest parts – never ceases to amaze. According to researchers in Canada and Singapore, velvet worm slime contains an ingredient that could revolutionize the design of high-performance polymers, making them far more sustainable than current versions.

“We have been investigating velvet worm slime as a model system for inspiring new adhesives and recyclable plastics because of its ability to reversibly form strong fibres,” explains Matthew Harrington, the McGill University chemist who co-led the research with Ali Miserez of Nanyang Technological University (NTU). “We needed to understand the mechanism that drives this reversible fibre formation, and we discovered a hitherto unknown feature of the proteins in the slime that might provide a very important clue in this context.”

The velvet worm (phylum Onychophora) is a small, caterpillar-like creature that lives in humid forests. Although several organisms, including spiders and mussels, produce protein-based slimy material outside their bodies, the slime of the velvet worm is unique. Produced from specialized papillae on each side of the worm’s head, and squirted out in jets whenever the worm needs to capture prey or defend itself, it quickly transforms from a sticky, viscoelastic gel into stiff, glassy fibres as strong as nylon.

When dissolved in water, these stiff fibres return to their biomolecular precursors. Remarkably, new fibres can then be drawn from the solution – implyimg that the instructions for fibre self-assembly are “encoded” within the precursors themselves, Harrington says.

High-molecular-weight protein identified

Previously, the molecular mechanisms behind this reversibility were little understood. In the present study, however, the researchers used protein sequencing and the AI-guided protein structure prediction algorithm AlphaFold to identify a specific high-molecular-weight protein in the slime. Known as a leucine-rich repeat, this protein has a structure similar to that of a cell surface receptor protein called a Toll-like receptor (TLR).

In biology, Miserez explains, this type of receptor is involved in immune system response. It also plays a role in embryonic or neural development. In the worm slime, however, that’s not the case.

“We have now unveiled a very different role for TLR proteins,” says Miserez, who works in NTU’s materials science and engineering department. “They play a structural, mechanical role and can be seen as a kind of ‘glue protein’ at the molecular level that brings together many other slime proteins to form the macroscopic fibres.”

Miserez adds that the team found this same protein in different species of velvet worms that diverged from a common ancestor nearly 400 million years ago. “This means that this different biological function is very ancient from an evolutionary perspective,” he explains.

“It was very unusual to find such a protein in the context of a biological material,” Harrington adds. “By predicting the protein’s structure and its ability to bind to other slime proteins, we were able to hypothesize its important role in the reversible fibre formation behaviour of the slime.”

The team’s hypothesis is that the reversibility of fibre formation is based on receptor-ligand interactions between several slime proteins. While Harrington acknowledges that much work remains to be done to verify this, he notes that such binding is a well-described principle in many groups of organisms, including bacteria, plants and animals. It is also crucial for cell adhesion, development and innate immunity. “If we can confirm this, it could provide inspiration for making high-performance non-toxic (bio)polymeric materials that are also recyclable,” he tells Physics World.

The study, which is detailed in PNAS, was mainly based on computational modelling and protein structure prediction. The next step, say the McGill researchers, is to purify or recombinantly express the proteins of interest and test their interactions in vitro.

The post Worm slime could inspire recyclable polymer design appeared first on Physics World.

In this episode of the Physics World Weekly podcast we explore the career opportunities open to physicists and engineers looking to work within healthcare – as medical physicists or clinical engineers.

Physics World’s Tami Freeman is in conversation with two early-career physicists working in the UK’s National Health Service (NHS). They are Rachel Allcock, a trainee clinical scientist at University Hospitals Coventry and Warwickshire NHS Trust, and George Bruce, a clinical scientist at NHS Greater Glasgow and Clyde. We also hear from Chris Watt, head of communications and public affairs at IPEM, about the new IPEM careers guide.

• This episode was created in collaboration with IPEM, the Institute of Physics and Engineering in Medicine. IPEM owns the journal Physics in Medicine & Biology.

The post Exploring careers in healthcare for physicists and engineers appeared first on Physics World.

If you dig deep enough, you’ll find that most biochemical and physiological processes rely on shuttling hydrogen atoms – protons – around living systems. Until recently, this proton transfer process was thought to occur when protons jump from water molecule to water molecule and between chains of amino acids. In 2023, however, researchers suggested that protons might, in fact, transfer at the same time as electrons. Scientists in Israel have now confirmed this is indeed the case, while also showing that proton movement is linked to the electrons’ spin, or magnetic moment. Since the properties of electron spin are defined by quantum mechanics, the new findings imply that essential life processes are intrinsically quantum in nature.

The scientists obtained this result by placing crystals of lysozyme – an enzyme commonly found in living organisms – on a magnetic substrate. Depending on the direction of the substrate’s magnetization, the spin of the electrons ejected from this substrate may be up or down. Once the electrons are ejected from the substrate, they enter the lysozymes. There, they become coupled to phonons, or vibrations of the crystal lattice.

Crucially, this coupling is not random. Instead, the chirality, or “handedness”, of the phonons determines which electron spin they will couple with – a  property known as chiral induced spin selectivity.

Excited chiral phonons mediate electron coupling spin

When the scientists turned their attention to proton transfer through the lysozymes, they discovered that the protons moved much more slowly with one magnetization direction than they did with the opposite. This connection between proton transfer and spin-selective electron transfer did not surprise Yossi Paltiel, who co-led the study with his Hebrew University of Jerusalem (HUJI) colleagues Naama Goren, Nir Keren and Oded Livnah in collaboration with Nurit Ashkenazy of Ben Gurion University and Ron Naaman of the Weizmann Institute.

“Proton transfer in living organisms occurs in a chiral environment and is an essential process,” Paltiel says. “Since protons also have spin, it was logical for us to try to relate proton transfer to electron spin in this work.”

The finding could shed light on proton hopping in biological environments, Paltiel tells Physics World. “It may ultimately help us understand how information and energy are transferred inside living cells, and perhaps even allow us to control this transfer in the future.

“The results also emphasize the role of chirality in biological processes,” he adds, “and show how quantum physics and biochemistry are fundamentally related.”

The HUJI team now plans to study how the coupling between the proton transfer process and the transfer of spin polarized electrons depends on specific biological environments. “We also want to find out to what extent the coupling affects the activity of cells,” Paltiel says.

Their present study is detailed in PNAS.

The post Quantum physics guides proton motion in biological systems appeared first on Physics World.

I began my career in the 1990s at a university spin-out company, working for a business that developed vibration sensors to monitor the condition of helicopter powertrains and rotating machinery. It was a job that led to a career developing technologies and techniques for checking the “health” of machines, such as planes, trains and trucks.

What a difference three decades has made. When I started out, we would deploy bespoke systems that generated limited amounts of data. These days, everything has gone digital and there’s almost more information than we can handle. We’re also seeing a growing use of machine learning and artificial intelligence (AI) to track how machines operate.

In fact, with AI being increasingly used in medical science – for example to predict a patient’s risk of heart attacks – I’ve noticed intriguing similarities between how we monitor the health of machines and the health of human bodies. Jet engines and hearts are very different objects, but in both cases monitoring devices gives us a set of digitized physical measurements.

A healthy perspective

Sensors installed on a machine provide various basic physical parameters, such as its temperature, pressure, flow rate or speed. More sophisticated devices can yield information about, say, its vibration, acoustic behaviour, or (for an engine) oil debris or quality. Bespoke sensors might even be added if an important or otherwise unchecked aspect of a machine’s performance needs to be monitored – provided the benefits of doing so outweigh the cost.

Generally speaking, the sensors you use in a particular situation depend on what’s worked before and whether you can exploit other measurements, such as those controlling the machine. But whatever sensors are used, the raw data then have to be processed and manipulated to extract particular features and characteristics.

If the machine appears to be going wrong, can you try to diagnose what the problem might be?

Once you’ve done all that, you can then determine the health of the machine, rather like in medicine. Is it performing normally? Does it seem to be developing a fault? If the machine appears to be going wrong, can you try to diagnose what the problem might be?

Generally, we do this by tracking a range of parameters to look for consistent behaviour, such as a steady increase, or by seeing if a parameter exceeds a pre-defined threshold. With further analysis, we can also try to predict the future state of the machine, work out what its remaining useful life might be, or decide if any maintenance needs scheduling.

A diagnosis typically involves linking various anomalous physical parameters (or symptoms) to a probable cause. As machines obey the laws of physics, a diagnosis can either be based on engineering knowledge or be driven by data – or sometimes the two together. If a concrete diagnosis can’t be made, you can still get a sense of where a problem might lie before carrying out further investigation or doing a detailed inspection.

One way of doing this is to use a “borescope” – essentially a long, flexible cable with a camera on the end. Rather like an endoscope in medicine, it allows you to look down narrow or difficult-to-reach cavities. But unlike medical imaging, which generally takes place in the controlled environment of a lab or clinic, machine data are typically acquired “in the field”. The resulting images can be tricky to interpret because the light is poor, the measurements are inconsistent, or the equipment hasn’t been used in the most effective way.

Even though it can be hard to work out what you’re seeing, in-situ visual inspections are vital as they provide evidence of a known condition, which can be directly linked to physical sensor measurements. It’s a kind of health status calibration. But if you want to get more robust results, it’s worth turning to advanced modelling techniques, such as deep neural networks.

One way to predict the wear and tear of a machine’s constituent parts is to use what’s known as a “digital twin”. Essentially a virtual replica of a physical object, a digital twin is created by building a detailed model and then feeding in real-time information from sensors and inspections. The twin basically mirrors the behaviour, characteristics and performance of the real object.

Real-time monitoring

Real-time health data are great because they allow machines to be serviced as and when required, rather than following a rigid maintenance schedule. For example, if a machine has been deployed heavily in a difficult environment, it can be serviced sooner, potentially preventing an unexpected failure. Conversely, if it’s been used relatively lightly and not shown any problems, then  maintenance could be postponed or reduced in scope. This saves time and money because the equipment will be out of action less than anticipated.

We can work out which parts will need repairing or replacing, when the maintenance will be required and who will do it

Having information about a machine’s condition at any point in time not only allows this kind of “intelligent maintenance” but also lets us use associated resources wisely. For example, we can work out which parts will need repairing or replacing, when the maintenance will be required and who will do it. Spare parts can therefore be ordered only when required, saving money and optimizing supply chains.

Real-time health-monitoring data are particularly useful for companies owning many machines of one kind, such as airlines with a fleet of planes or haulage companies with a lot of trucks. It gives them a better understanding not just of how machines behave individually – but also collectively to give a “fleet-wide” view. Noticing and diagnosing failures from data becomes an iterative process, helping manufacturers create new or improved machine designs.

This all sounds great, but in some respects, it’s harder to understand a machine than a human. People can be taken to hospitals or clinics for a medical scan, but a wind turbine or jet engine, say, can’t be readily accessed, switched off or sent for treatment. Machines also can’t tell us exactly how they feel.

However, even humans don’t always know when there’s something wrong. That’s why it’s worth us taking a leaf from industry’s book and consider getting regular health monitoring and checks. There are lots of brilliant apps out there to monitor and track your heart rate, blood pressure, physical activity and sugar levels.

Just as with a machine, you can avoid unexpected failure, reduce your maintenance costs, and make yourself more efficient and reliable. You could, potentially, even live longer too.

The post People benefit from medicine, but machines need healthcare too appeared first on Physics World.