Innovative target design leads to surprising discovery in laser-plasma acceleration

Researchers studying laser-driven proton acceleration introduced an innovative, self-replenishing water sheet target to address the inefficiency of replacing targets after each laser pulse. The target had a surprising side effect, resulting in a naturally focused, more tightly aligned proton beam. 
Image Credit: Greg Stewart/SLAC National Accelerator Laboratory)

Scientists have developed a groundbreaking method for generating fast, bright proton beams using a high-repetition-rate laser-plasma accelerator. This work, published in Nature Communications, resolves several long-standing challenges and ushers this technology to the threshold of real-world applications – all thanks to a stream of water. 

“These exciting results pave the way for new applications of relativistic high-power lasers for applications in medicine, accelerator research, and inertial fusion,” said Siegfried Glenzer, professor of photon science and the director of the High Energy Density Science division at the Department of Energy's SLAC National Accelerator Laboratory. 

Women of Science: A Legacy of Achievement

Future generations to pursue their passions and break down barriers in the pursuit of knowledge.
Image Credit: Scientific Frontline stock image

Throughout history, women have made groundbreaking contributions to science, despite facing significant societal barriers and a lack of recognition. Their relentless pursuit of knowledge and innovation has shaped our understanding of the world and paved the way for future generations of scientists. This article celebrates the achievements of some of these remarkable women, highlighting their struggles and the impact of their work.

The women featured in this article, along with countless others throughout history, have made invaluable contributions to the advancement of science. Their achievements, often accomplished in the face of adversity and societal barriers, have shaped our understanding of the world and paved the way for future generations of scientists. These women demonstrate the power of perseverance, the importance of challenging established norms, and the profound impact that individual dedication can have on scientific progress. By recognizing and celebrating their legacies, we not only honor their contributions but also inspire future generations to pursue their passions and break down barriers in the pursuit of knowledge.

First distributed quantum algorithm brings quantum supercomputers closer

Dougal Main and Beth Nichol working on the distributed quantum computer.
Photo Credit: John Cairns.

In a milestone that brings quantum computing tangibly closer to large-scale practical use, scientists at Oxford University’s Department of Physics have demonstrated the first instance of distributed quantum computing. Using a photonic network interface, they successfully linked two separate quantum processors to form a single, fully connected quantum computer, paving the way to tackling computational challenges previously out of reach. The results have been published in Nature. 

The breakthrough addresses quantum’s ‘scalability problem’: a quantum computer powerful enough to be industry-disrupting would have to be capable of processing millions of qubits. Packing all these processors in a single device, however, would require a machine of an immense size. In this new approach, small quantum devices are linked together, enabling computations to be distributed across the network. In theory, there is no limit to the number of processors that could be in the network.  

Novel processor uses magnons to crack complex problems

The three first authors of the paper - Noura Zenbaa (on the right), Claas Abert (on the left) and Fabian Majcen (in the middle) at the moment when the universal inverse-design magnonic device was activated to solve its first problem.
Photo Credit: Andrii Chumak, NanoMag, U of Vienna

An international team of researchers, led by physicists from the University of Vienna, has achieved a breakthrough in data processing by employing an "inverse-design" approach. This method allows algorithms to configure a system based on desired functions, bypassing manual design and complex simulations. The result is a smart "universal" device that uses spin waves ("magnons") to perform multiple data processing tasks with exceptional energy efficiency. Published in Nature Electronics, this innovation marks a transformative advance in unconventional computing, with significant potential for next-generation telecommunications, computing, and neuromorphic systems.

Modern electronics face critical challenges, including high energy consumption and increasing design complexity. In this context, magnonics — the use of magnons, or quantized spin waves in magnetic materials — offers a promising alternative. Magnons enable efficient data transport and processing with minimal energy loss. With the growing demand for innovative computing solutions, ranging from 5G and upcoming 6G networks to neuromorphic computing (mimicking functions of the brain), magnonics represents a paradigm shift that redefines how devices are designed and operated. Developing an innovative magnonic processor that enables highly adaptive and energy-efficient computing was a challenge that Andrii Chumak of the University of Vienna's Nanomagnetism and Magnonics Group and his collaborators successfully met.

The metal that does not expand

Metal usually expands when heated
Photo Credit: Courtesy of Technische Universität Wien

Breakthrough in materials research: an alloy of several metals has been developed that shows practically no thermal expansion over an extremely large temperature interval.

Most metals expand when their temperature rises. The Eiffel Tower, for example, is around 10 to 15 centimeters taller in summer than in winter due to its thermal expansion. However, this effect is extremely undesirable for many technical applications. For this reason, the search has long been on for materials that always have the same length regardless of the temperature. Invar, for example, an alloy of iron and nickel, is known for its extremely low thermal expansion. How this property can be explained physically, however, was not entirely clear until now.

Now, a collaboration between theoretical researchers at TU Wien (Vienna) and experimentalists at University of Science and Technology Beijing has led to a decisive breakthrough: using complex computer simulations, it has been possible to understand the invar effect in detail and thus develop a so-called pyrochlore magnet – an alloy that has even better thermal expansion properties than invar. Over an extremely wide temperature range of over 400 Kelvins, its length only changes by around one ten-thousandth of one per cent per Kelvin.

Spinning or not spinning?

Opening the "Gate of Truth" of puzzling superconductivity in strontium ruthenate
Image Credit: KyotoU/G Mattoni

Superconductors can carry electricity without losing energy, a superpower that makes them invaluable for a range of sought-after applications, from maglev trains to quantum computers. Generally, this comes at the price of having to keep them extremely cold, an opportunity cost that has frequently hindered widespread use.

Understanding of how superconductors work has also progressed, but there still remains a great deal about them that is unknown. For example, amongst many materials known to have superconducting properties, some do not behave according to conventional theory.

One such puzzling material is strontium ruthenate or Sr2RuO4, which has challenged scientists since it was discovered to be a superconductor in 1994. Initially, researchers thought this material had a special type of superconductivity called a "spin-triplet" state, which is notable for its spin supercurrent. But even after considerable investigation, a full understanding of its behavior has remained a mystery.

Even Quantum Physics Obeys the Law of Entropy

Image Credit: Courtesy of Technische Universität Wien

Is there a contradiction between quantum theory and thermodynamics? On the surface, yes - but at TU Wien, researchers have now shown how the two fit together perfectly.

It is one of the most important laws of nature that we know: The famous second law of thermodynamics says that the world gets more and more disordered when random chance is at play. Or, to put it more precisely: That entropy must increase in every closed system. Ordered structures lose their order, regular ice crystals turn into water, porcelain vases are broken up into shards. At first glance, however, quantum physics does not really seem to adhere to this rule: Mathematically speaking, entropy in quantum systems always remains the same.

A research team at TU Wien has now taken a closer look at this apparent contradiction and has been able to show: It depends on what kind of entropy you look at. If you define the concept of entropy in a way that it compatible with the basic ideas of quantum physics, then there is no longer any contradiction between quantum physics and thermodynamics. Entropy also increases in initially ordered quantum systems until it reaches a final state of disorder.

Neutrons reveal lithium flow could boost performance in solid-state battery

Scientists from Duke University and ORNL used neutron scattering to see how lithium ions, represented by the glowing orbs, move through a diffusion gate, represented by the gold triangle, in a solid-state electrolyte.
Image Credit: Phoenix Pleasant/ORNL, U.S. Dept. of Energy

A team of scientists led by a professor from Duke University discovered a way to help make batteries safer, charge faster and last longer. They relied on neutrons at the Department of Energy’s Oak Ridge National Laboratory to understand at the atomic scale how lithium moves in lithium phosphorus sulfur chloride (Li6PS5Cl), a promising new type of solid-state battery material known as a superionic compound. 

Using neutrons at ORNL’s Spallation Neutron Source (SNS), and machine-learned molecular dynamics simulations at the National Energy Research Scientific Computing Center at Lawrence Berkeley National Laboratory, they found that lithium ions easily diffused in the solid material, as they do in liquid electrolytes, allowing faster, safer charging. The results, published in Nature Physics, could bring the best of both worlds for solid-state electrolytes, or SSEs, enabling next-generation batteries.  

“Our research was about figuring out what is going on inside these materials using the power of neutron scattering and large-scale computer simulations,” said Olivier Delaire, associate professor of mechanical engineering, materials science, chemistry and physics at Duke University. Delaire arrived at ORNL in 2008 as a Clifford G. Shull Fellow and won DOE’s Office of Science Early Career Award in 2014. Today, he leads a research group at Duke dedicated to investigating the atomic structure and dynamics of energy materials.

A new experimental system to bring quantum technologies closer to students

The expert Raúl Lahoz and a group of students with the new equipment for studying quantum physics.
 Photo Credit: Fundació Catalunya La Pedrera

The world of quantum physics is experiencing a second revolution, which will drive an exponential leap in the progress of computing, the internet, telecommunications, cybersecurity and biomedicine. Quantum technologies are attracting more and more students who want to learn about concepts from the subatomic world — such as quantum entanglement or quantum superposition — to explore the innovative potential of quantum science. In fact, understanding the non-intuitive nature of quantum technology concepts and recognizing their relevance to technological progress is one of the challenges of 2025, declared the International Year of Quantum Science and Technology by UNESCO.

Now, a team from the Faculty of Physics of the University of Barcelona has designed new experimental equipment that makes it possible for students to familiarize themselves with the more complex concepts of quantum physics. The configuration they present —versatile, cost-effective and with multiple ways of application in the classroom — is already operational in the Advanced Quantum Laboratory of the UB’s Faculty of Physics and could also be accessible in less specialized centers.

This innovation is presented in an article in the journal EPJ Quantum Technology, which results from a collaboration between professors Bruno Juliá, from the Department of Quantum Physics and Astrophysics and the UB Institute of Cosmos Sciences (ICCUB); Martí Duocastella, from the Department of Applied Physics and the UB Institute of Nanoscience and Nanotechnology (IN2UB), and José M. Gómez, from the Department of Electronic and Biomedical Engineering. It is based on the result of Raúl Lahoz’s master’s final project, with the participation of experts Lidia Lozano and Adrià Brú.

Engineering Quantum Entanglement at the Nanoscale

Study authors P. James Schuck (left) and Chiara Trovatello from the Schuck lab at Columbia Engineering.
Photo Credit: Jane Nisselson/Columbia Engineering

Physicists have spent more than a century measuring and making sense of the strange ways that photons, electrons, and other subatomic particles interact at extremely small scales. Engineers have spent decades figuring out how to take advantage of these phenomena to create new technologies.

In one such phenomenon, called quantum entanglement, pairs of photons become interconnected in such a way that the state of one photon instantly changes to match the state of its paired photon, no matter how far apart they are. 

Nearly 80 years ago, Albert Einstein referred to this phenomenon as "spooky action at a distance." Today, entanglement is the subject of research programs across the world — and it’s becoming a favored way to implement the most fundamental form of quantum information, the qubit. 

Quantum simulators: When nature reveals its natural laws

Photo Credit: © Oliver Diekmann/TU Wien

Quantum simulators are a completely new tool for research: quantum physics is studied by other kinds of quantum physics. Research teams from Innsbruck and Vienna are developing a new method that will allow this new technology to be reliably verified.

Quantum physics is a very diverse field: it describes particle collisions shortly after the Big Bang as well as electrons in solid materials or atoms far out in space. But not all quantum objects are equally easy to study. For some – such as the early universe – direct experiments are not possible at all. However, in many cases quantum simulators can be used instead: One quantum system (for example, a cloud of ultracold atoms) is studied in order to learn something about another system that looks physically very different, but still follows the same laws, i.e. adheres to the same mathematical equations.

It is often difficult to find out which equations determine a particular quantum system. Normally, one first has to make theoretical assumptions and then conduct experiments to check whether these assumptions prove correct. Strikingly, researchers at the University of Innsbruck, opens an external URL in a new window, the Institute of Quantum Optics and Quantum Information, opens an external URL in a new window (IQOQI) and TU Wien (Vienna) have now jointly achieved an important step in this field: they have developed a method that allows them to read directly from the experiment which physical theory effectively describes the behavior of the quantum system. This now allows for a new kind of quality control: it is possible to directly check whether the quantum simulator actually does what it is supposed to simulate. This should enable quantitative statements to be made about quantum systems that cannot be investigated directly.

Kerr-Enhanced Optical Spring for Next-Generation Gravitational Wave Detectors

A novel technique for enhancing optical spring that utilizes the Kerr effect to improve the sensitivity of gravitational wave detectors (GWDs) has recently been developed by scientists at Tokyo Tech. This innovative design uses optical non-linear effects from the Kerr effect in the Fabry-Perot cavity to achieve high signal amplification ratios and optical spring constant, with potential applications in not only GWDs but also in a range of optomechanical systems.

The detection of gravitational waves stands as one of the most significant achievements in modern physics. In 2017, gravitational waves from the merger of a binary neutron star were detected for the first time which uncovered crucial information about our universe, from the origin of short gamma-ray bursts to the formation of heavy elements. However, detecting gravitational waves emerging from post-merger remnants has remained elusive due to their frequency range lying outside the range of modern gravitational wave detectors (GWDs). These elusive waves hold important insights into the internal structure of neutron stars, and since these waves can be observed once every few decades by modern GWDs, there is an urgent need for next-generation GWDs.

One way to enhance the sensitivity of GWDs is signal amplification using an optical spring. Optical springs, unlike their mechanical counterparts, leverage radiation pressure force from light to mimic spring-like behavior. The stiffness of optical springs, such as in GWDs, is determined by the light power within the optical cavity. Thus, enhancing the resonant frequency of optical springs requires increasing the intracavity light power which, however, can result in thermally harmful effects and prevent the detector from working properly.

Chemical reactions can scramble quantum information as well as black holes

Rice University theorist Peter Wolynes and collaborators at the University of Illinois Urbana-Champaign have shown that molecules can be as formidable at scrambling quantum information as black holes.
Image Credit: Courtesy of Martin Gruebele; DeepAI was used in image production

If you were to throw a message in a bottle into a black hole, all of the information in it, down to the quantum level, would become completely scrambled. Because in black holes this scrambling happens as quickly and thoroughly as quantum mechanics allows, they are generally considered nature’s ultimate information scramblers.

New research from Rice University theorist Peter Wolynes and collaborators at the University of Illinois Urbana-Champaign, however, shows that molecules can be as formidable at scrambling quantum information as black holes. Combining mathematical tools from black hole physics and chemical physics, they have shown that quantum information scrambling takes place in chemical reactions and can nearly reach the same quantum mechanical limit as it does in black holes. The work is published online in the Proceedings of the National Academy of Sciences.

“This study addresses a long-standing problem in chemical physics, which has to do with the question of how fast quantum information gets scrambled in molecules,” Wolynes said. “When people think about a reaction where two molecules come together, they think the atoms only perform a single motion where a bond is made or a bond is broken.

“It’s ultimately about predicting everything” – theory could be a map to hunted quantum materials

Photo Credit: Vendi Jukic Buca

A breakthrough in theoretical physics is an important step towards predicting the behavior of the fundamental matter of which our world is built. It can be used to calculate systems of enormous quantities of quantum particles, a feat thought impossible before. The University of Copenhagen research may prove of great importance for the design of quantum computers and could even be a map to superconductors that function at room-temperature.

On the fringes of theoretical physics, Berislav Buca investigates the nearly impossible by way of "exotic" mathematics. His latest theory is no exception. By making it possible to calculate the dynamics, i.e., movements and interactions, of systems with enormous quantities of quantum particles, it has delivered something that had been written off in physics. An impossibility made possible.

The unexpected presence of a white cat adorns the illustrations of Buca's research. Pulci the cat is his eye-catching muse. Arrows through the cat's body illustrate the quantum mechanical origin of the playful cat's movements – and this is precisely the relationship that Buca is trying to understand by making it possible to calculate the dynamics of the very smallest particles.

The breakthrough has reinvigorated an old and fundamental scientific question: Theoretically, if all behavior in the universe can be calculated by way of the laws of physics, can we then predict everything by calculating its smallest particles? 

Heat flows the secret to order in prebiotic molecular kitchen

Schematic visualization of heat flows in rock cracks.
Illustration Credit: Christof Mast

Life is complicated. What is true for our everyday existence also holds for the many complex processes that take place inside cells. Proteins constantly have to be synthesized, cell walls built, and DNA replicated. This can only work when reaction partners converge at the right time in sufficiently high concentrations while suffering little disruption from other substances. Over the course of billions of years, evolution has perfected these mechanisms and ensured that such vital processes occur with high efficiency at the correct place.

Circumstances were probably a lot more chaotic four billion years ago, when prebiotic reactions created the conditions for the emergence of the first lifeforms. For these reactions, too, it was necessary for the ‘right’ substances to be brought together at the ‘right’ time in one place, so that more complex biomolecules like RNA and amino acid chains could form. While such reactions are possible to recreate in the laboratory thanks to manual intermediate steps, it is highly challenging for them to come about in a simple ‘primordial soup’ – that is to say, a very dilute mixture of prebiotic building blocks. So how could nature create suitable conditions for the origin of life?

Physics of Complex Fluids: Ring Polymers Show Unexpected Motion Patterns Under Shear

Schematic of poly[2]catenane slip tumbling and bonded ring gradient tumbling.
Illustration Credit: Reyhaneh A. Farimani

An international research team is attracting the attention of experts in the field with computational results on the behavior of ring polymers under shear forces: Reyhaneh Farimani, University of Vienna, and her colleagues showed that for the simplest case of connected ring pairs, the type of linkage – chemically bonded vs. mechanically linked – has profound effects on the dynamic properties under continuous shear. In these cases, novel rheological patterns emerge. In addition to being recently published in the prestigious journal Physical Review Letters, the study received an "Editors' Suggestion" for its particular novelty.

The shearing of fluids – meaning the sliding of fluid layers over each other under shear forces – is an important concept in nature and in rheology, the science that studies the flow behavior of matter, including liquids and soft solids. Shear forces are lateral forces applied parallel to a material, inducing deformation or slippage between its layers. Fluid shear experiments allow the characterization of important rheological properties such as viscosity (resistance to deformation or flow) and thixotropy (decrease in viscosity under the influence of shear) which are important in applications ranging from industrial processes to medicine. Studies on the shear behavior of viscoelastic fluids, created by introducing polymers into Newtonian fluids, have already been conducted in recent years. However, a novel approach in the current research involves the consideration of polymer topology – the spatial arrangement and structure of molecules – by using ring polymers. Ring polymers are macromolecules composed of repeating units, forming closed loops without free ends. 

Self-assembly of complex systems: hexagonal building blocks are better

Professor Erwin Frey
Photo Credit: © Benjamin Asher / Ludwig-Maximilians-Universität München

Complex systems in nature, like their synthetic counterparts in technology, comprise a large number of small components that assemble of their own accord through molecular interactions. Gaining a better understanding of the principles and mechanisms of this self-assembly is important for the development of new applications in domains such as nanotechnology and medicine.

Professor Erwin Frey, Chair of Statistical and Biological Physics at LMU and member of the ORIGINS Excellence Cluster, and his research fellow Dr. Florian Gartner has now investigated an aspect of self-assembly that has received little attention before now: What role do the shape and the number of possible bonds between particles play? As the researchers report in the journal Physical Review X, their results show that hexagonal morphologies – in other words, six-sided structures – such as molecules with six binding sites are ideal for self-assembly.

Kapitza-Dirac effect used to show temporal evolution of electron waves

Time dependent interference fringes from the ultrafast Kapitza Dirac Effect. An electron wave packet is exposed to two counterpropagating ultrashort laser pulses. The time span from back to front is 10 pico seconds.
Illustration Credit: © Goethe University Frankfurt

One of the most fundamental interactions in physics is that of electrons and light. In an experiment at Goethe University Frankfurt, scientists have now managed to observe what is known as the Kapitza-Dirac effect for the first time in full temporal resolution. This effect was first postulated over 90 years ago, but only now are its finest details coming to light. 

It was one of the biggest surprises in the history of science: In the early days of quantum physics around 100 years ago, scholars discovered that the particles which make up our matter always behave like waves. Just as light can scatter at a double slit and produce scattering patterns, electrons can also display interference effects. In 1933, the two theorists Piotr Kapitza and Paul Dirac proved that an electron beam is even diffracted from a standing light wave (due to the particles' properties) and that interference effects as a result of the wave properties are to be expected. 

A German-Chinese team led by Professor Reinhard Dörner from Goethe University Frankfurt has succeeded in using this Kapitza-Dirac effect to visualize even the temporal evolution of the electron waves, known as the electrons' quantum mechanical phase. The researchers have now presented their results in the journal Science. 

‘Frankenstein design’ enables 3D printed neutron collimator

Images of the 3D printed “Frankenstein design” collimator show the “scars” where the individual parts are joined, which are clearly visible at right.
Photo Credit: Genevieve Martin/ORNL, U.S. Dept. of Energy

The time-tested strategy of divide and conquer took on a new, high-tech meaning during neutron experiments by scientists at the Department of Energy’s Oak Ridge National Laboratory. They discovered that the problems they faced while attempting to 3D print a one-piece collimator could be solved by instead developing a “Frankenstein design” involving multiple body parts – and some rather obvious scars.

Collimators are important components used in neutron scattering. Similar to X-rays, neutrons are used to study energy and matter at the atomic scale. Neutron collimators can be thought of as funnels that help guide neutrons toward a detector after they interact with experimental sample materials. These funnels primarily serve to reduce the number of stray neutrons that interfere with data collection, for example, neutrons that scatter off sample holders, or from other apparatuses used in the experiment such as high-pressure cells. 

During this process, most of the unwanted neutrons, those scattering from features other than the sample, enter channels inside the collimators at odd angles and are absorbed by channel walls, also referred to as blades. The blades act like the gutters on a bowling lane, which capture bowling balls that are not headed toward the pins.

Magnetic Avalanche Triggered by Quantum Effects

Christopher Simon holds a crystal of lithium holmium yttrium fluoride.
Photo Credit: Lance Hayashida/Caltech

Iron screws and other so-called ferromagnetic materials are made up of atoms with electrons that act like little magnets. Normally, the orientations of the magnets are aligned within one region of the material but are not aligned from one region to the next. Think of groups of tourists in Times Square pointing to different billboards all around them. But when a magnetic field is applied, the orientations of the magnets, or spins, in the different regions line up and the material becomes fully magnetized. This would be like the packs of tourists all turning to point at the same sign.

The process of spins lining up, however, does not happen all at once. Rather, when the magnetic field is applied, different regions, or so-called domains, influence others nearby, and the changes spread across the material in a clumpy fashion. Scientists often compare this effect to an avalanche of snow, where one small lump of snow starts falling, pushing on other nearby lumps, until the entire mountainside of snow is tumbling down in the same direction.