Physicists have long suspected that a peculiar quantum state lurks inside a class of materials known as kagome metals, but proving its existence has been elusive. Now, a team led by Yeongkwan Kim at the Korea Advanced Institute of Science and Technology has performed experiments on a kagome metal that provide the strongest evidence yet for this exotic state.
Published in Nature Physics, the team’s results could shed new light on how these materials transition into superconductivity.
Researchers at European XFEL, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Rostock University and other collaborating institutions have used high-precision experiments to demonstrate that the most widely used models for the behavior of electrons in warm dense matter are inaccurate. Warm dense matter is challenging to study, but also is of key importance for a plethora of research, including the investigation of planetary interiors, materials science and laser fusion experiments. The study is published in Physical Review Letters.
In warm dense matter, electron density oscillates. The collective oscillations are called plasmons. They carry important information and can be observed using X-rays, resulting in scattering spectra—abstract images captured by a detector. In many experiments, these spectra are interpreted using simplified uniform electron gas models. However, the new measurements show that for warm dense aluminum, these models consistently overestimate the plasmon energy by up to about 25% (about 8 electronvolts) and fail to reproduce the full measured shape of the signal.
“Our measurements are precise enough to clearly distinguish between competing models,” says Dr. Thomas Preston of European XFEL. “That is important because these models are widely used to diagnose extreme states of matter. If the model is incorrect, that leads to inaccurately inferred properties.”
Researchers have demonstrated a new way to make spatially separated lasers synchronize and act as a single coherent light source—without extreme conditions or complex materials.
A team of physicists from the University of Southampton (UK), University of Warsaw (PL), Military University of Technology (PL), Institut Pascal, Université Clermont Auvergne, CNRS (FR), and CNR (IT) has developed a new class of tunable photonic devices in which multiple tiny laser beams spontaneously synchronize and behave as a unified, spatially extended and coherent light source. Remarkably, this effect is achieved at room temperature using a simple system based on liquid crystals and organic dye molecules, opening new possibilities for low-cost and reconfigurable optical technologies.
The work is published in the journal Nature Communications. The study demonstrates that spatially separated laser spots inside an optical microcavity can spontaneously phase-lock—that is, align (or synchronize) their oscillations—and form a collective state known as a “supermode.” Traditionally, such behavior has been observed only in highly specialized semiconductor systems operating at cryogenic temperatures and in the so-called strong light-matter coupling regime.
Today’s refrigerants, which are specialized working fluids used in air conditioners, refrigerators and heat pumps, come with a host of issues, including leakage, emissions concerns, flammability and limited reclamation of used refrigerants. However, a recent study by University of Notre Dame researchers published in Materials Horizons describes a promising alternative for next-generation cooling using thermoelectric technology, which has no moving parts and no gaseous refrigerants, allowing for zero leaks.
“By making thermoelectric devices a competitive and commercially viable technology, it can transform the way we cool things,” said Yanliang Zhang, Advanced Materials and Manufacturing Collegiate Professor of Aerospace and Mechanical Engineering at Notre Dame. “We can make the cooling process become very environmentally friendly.”
In the past, widespread adoption of thermoelectrics has been challenging because of the high costs associated with traditional manufacturing processes. However, the research team led by Zhang has developed an innovative ink-based printing strategy that enables scalable manufacturing of low-cost, high-performance thermoelectric materials and devices.
University of Florida researchers are exploring how lasers could help astronauts build structures on the moon using materials already available there, including lunar soil transformed into glass. The work, led by Victoria M. Miller, Ph.D., an associate professor in the Herbert Wertheim College of Engineering and researcher with the UF Astraeus Space Institute, recently completed a research phase focused on laser forming, a manufacturing process that bends materials without physical contact.
The team’s latest paper, published in Lasers in Manufacturing and Materials Processing, examined how different atmospheric conditions affect laser bending, an important question for future manufacturing in the vacuum of space. The long-term applications extend beyond space exploration and could also support flexible manufacturing efforts on Earth.
“It is also for Earth applications. We’re focused on flexible manufacturing for defense applications,” said Miller, who works in the Department of Materials Science and Engineering.
Researchers at the National Graphene Institute, in collaboration with the National University of Singapore, have shown that the magnetic behavior of electrons in graphene can be precisely controlled using electricity, revealing unusually large spin signals in a carefully engineered graphene system.
The study, published in Nature Communications, demonstrates how placing graphene close to a magnetic material can influence the spin of electrons without permanently altering graphene itself. By combining this magnetic proximity effect with graphene superlattices and operating at very low charge densities, the researchers were able to strongly tune how spins move through the material.
“This work shows that by combining graphene with nearby magnetic materials, we can gain a high level of control over electron spin using electrical signals alone,” said Dr. Daniel Burrow, from the University of Manchester. “In simple terms, we are learning how to pass information through graphene using the spin of electrons rather than their electrical charge.”
Physicists have long been drawn to the nonlinear Hall effect: a subtle variant of the classical Hall effect, in which an electric voltage appears perpendicular to a current flowing through a material. Unlike its classical counterpart, the nonlinear version can arise even without breaking time-reversal symmetry, and its magnitude is tied to deep geometric properties of electron wave functions. So far, however, the behavior of the effect when a magnetic field is applied has remained poorly understood.
Through new research published in Physical Review Letters, a team led by Jinrui Zhong at the Beijing Institute of Technology has shed new light on this question—leading them to discover an entirely new class of quantum oscillation.
A research team from Tohoku University and Kyocera Corp. has developed a new magneto-optical material—a nanocomposite magnetic garnet film—that can be deposited directly onto silicon substrates while delivering a magneto-optical figure of merit four times higher than conventional polycrystalline films.
Using this material, the team demonstrated a monolithically integrated optical isolator on a silicon chip that matches the performance of conventional devices but with a far simpler, seed-layer-free structure. The breakthrough opens a practical path toward large-scale deployment of silicon photonics in AI-era data centers.
The work is published in the journal ACS Applied Optical Materials.
Amorphous materials such as glass are solids whose internal structure lacks a repeating pattern. Their molecules are arranged in a random and irregular way. Surprisingly, these disordered materials can “remember” past mechanical experiences; that is, the way they respond to a force can depend on how they have responded to external forces before.
Roni Chatterjee and Smarajit Karmakar at the Tata Institute of Fundamental Research, Hyderabad, in collaboration with Damien Vandembroucq (CNRS, ESPCI Paris, France) and Muhittin Mungan (Heinrich Heine University Düsseldorf, Germany) now report crucial insights into memory formation in amorphous solids. Their study reveals that amorphous materials can encode memories even when the applied deformations are completely random rather than perfectly periodic, challenging the conventional understanding of memory formation in disordered solids. The findings of this study have been published in the New Journal of Physics.
Researchers usually study this kind of memory under strictly controlled laboratory conditions. They repeatedly deform a material in a regular, predictable way, gently shearing it back and forth over many cycles. Over time, the material “learns” this pattern and settles into a state that reflects its past training. This has been the standard way to understand memory in such systems.
Certain substances can become magnetic when exposed to an external magnetic field. Magnetic susceptibility measures how easily a material can be magnetized. Materials known as organic radicals have been noted to possess anomalously large magnetic susceptibility. However, researchers have been unable to explain this phenomenon using conventional theories.
Now, researchers at the University of Osaka have developed a theoretical framework to explain this anomalous magnetic susceptibility. This discovery was recently published in the Journal of Physical Chemistry Letters.