A technique for determining the magnetic structure of materials gets a theoretical makeover that can cope with nonrandom, temporally correlated fluctuations.
Category: materials – Page 15
Engineers observe quantum heat waves at room temperature
Efficient heat management in solids is key to advancing the next generation of electronics. However, wave-like heat movement—known as phonon focusing—had been observed only at extremely low, or cryogenic, temperatures, limiting its study and practical use.
Now, researchers at the UCLA Samueli School of Engineering have demonstrated that phonons, atomic heat-carrying vibrations with quantum properties, can travel in focused, raylike paths at room temperature. Instead of spreading uniformly in all directions, heat can move along guided pathways defined by a material’s crystal structure, opening new possibilities for managing heat flow in future electronics and quantum technologies.
New research shows how ‘hot electrons’ can reshape metals in billionths of a second
Researchers at The University of Manchester have revealed how intense electronic excitation can trigger rapid structural changes in metals—without heating the atomic lattice—offering new insight into ultrafast materials behavior.
When metals are exposed to powerful laser pulses, their electrons can heat up almost instantly, reaching extreme temperatures while the atoms themselves remain relatively cold. This study shows that, under these conditions, the behavior of the material is driven not by heat in the traditional sense, but by changes in the electronic system.
Published in Physical Review Materials, the research, led by Dr. Sam Azadi, demonstrates that this electronic “reheating” alone can cause metals to switch between different crystal structures in a fraction of a picosecond.
Simple semiconductor films break light’s front-back symmetry
Light typically interacts with a material the same way whether it enters through the front or the back—like polarized sunglasses that work the same from either side. Cornell researchers have demonstrated a simple route to breaking that symmetry, opening new possibilities for photonics and quantum information processing.
Optical reciprocity, the principle that a system responds identically regardless of which side faces the light, underlies most lenses, mirrors and other optical devices. A new study published in Nature Materials demonstrates that some materials can be engineered to exhibit nonreciprocal absorption and emission of linearly polarized light.
“Imagine window blinds with sunlight coming through their horizontal slats, but from the opposite side, the same blinds let light through as if the slats were vertical, completely inverted,” said corresponding author Richard Robinson, professor of materials science and engineering in the Cornell Duffield College of Engineering. “To get this type of behavior, you typically need complex metamaterials or external magnetic fields, but we show that it can be achieved in simple, solution-processed semiconductor nanoclusters.”
New sensing method measures laser-cutting depth by tracking vaporization recoil
Laser dicing, a technique that uses focused laser pulses to separate individual chips from a semiconductor wafer, is increasingly favored over mechanical blade cutting because it can process delicate, low-strength materials with minimal physical stress. However, achieving proper yield requires precise control over the process.
If pulses fall short, they leave a wafer only partially cut, while excessive pulses can damage the material or the tape used to hold it. While techniques for monitoring processing depth exist, most are too slow or fragile for use on production lines.
Now, a team of researchers led by Professor Hirofumi Hidai from the Graduate School of Engineering, Chiba University, Japan, focused on a different signal: recoil force. Recoil force is the minute reaction force generated on a material’s surface when it is rapidly heated and vaporized by a laser pulse.
Light reveals transient electronic step behind a hidden state in metal-organic framework
A fleeting photoinduced electronic state and the subsequent formation of a photoinduced hidden state in a metal–organic framework were captured in just 30 femtoseconds by researchers at Science Tokyo, Tohoku University and Nagoya Institute of Technology, Japan. By combining ultrafast laser spectroscopy with theoretical analysis, the researchers found that a transient electronic state plays a key role in this process. The findings provide new insights into controlling material properties with light for future applications.
When materials absorb light, they can enter unusual states with properties that differ from their normal behavior. These photoinduced states offer scientists a way to control material properties beyond what can be achieved through heating or cooling. Understanding how such states emerge on ultrafast timescales is essential for designing future photoresponsive materials and advanced optical technologies.
However, the earliest stages of photoinduced state formation can occur on the femtosecond (fs) timescale (a millionth of a billionth of a second), making it extremely difficult to observe and understand the process. To overcome this, a research team led by Assistant Professor Tadahiko Ishikawa from the Department of Chemistry, School of Science, Institute of Science Tokyo (Science Tokyo), Japan, along with doctoral student Samiran Banu (currently a Special Postdoctoral Researcher at RIKEN), conducted a study in collaboration with researchers from Tohoku University and Nagoya Institute of Technology, Japan.
Faster fracture tests offer path to more sustainable material choices
Recycled materials promise a cleaner future, but recycled content alone does not necessarily make a product sustainable. At Georgia Tech’s Daedalus Lab, assistant professor Christos Athanasiou and postdoctoral researcher Danqi Sun are working to provide greater certainty to designers and engineers by rethinking how materials are tested for their fracture characteristics.
Their article in Science Advances details a new testing protocol that reduces costs, increases speed and simulates real-world conditions.
Materials shape nearly every part of modern life, from packaging and consumer products to bridges and medical devices. Choosing the right material involves balancing durability, cost, manufacturability and environmental impact. Yet those decisions are not always guided by a clear understanding of how materials age and fail under real-world conditions, especially for recycled materials like plastics.
Exploring a smarter way to build climate-resilient roads
Every year from June to September, India experiences the monsoon season. While the visible heavy rainfall often takes the blame for many roads requiring repairs much sooner than expected, a far less visible yet critical force is at play long before the first raindrop falls on the road.
Rigid, or concrete, pavements are a type of road construction that uses concrete slabs. They distribute traffic loads over a wide area and can withstand heavy loads. These pavements are used in places like highways and airports and are becoming increasingly popular on city roads as well.
What is interesting is that, together with their surrounding environments, concrete pavements form an integrated system. Daily temperature fluctuations, such as those due to sunlight and cool nights, along with seasonal changes, result in cycles of heating and cooling of the pavement layers. It is these cycles that create internal stresses within the pavement structure.
When It Comes to Fusion, Materials Matter
In the experiment, researchers used two different methods to pack deuterium, a heavy form of hydrogen atoms that is often used in fusion, into thin foils of palladium and titanium. They then fired a beam of deuterium ions at the foils at different energies and measured how often fusion happened. Then they compared the rates from the different materials and methods with the “bare” fusion reaction (not in a material).
The team found that fusion rates depended on how the deuterium was loaded into the metal foils. The biggest effect was at the lowest energies, below 2.5 kiloelectronvolts (keV), where theory predicts fusion rates drop off sharply. Instead, researchers found a surprising plateau: Some samples showed elevated fusion rates roughly a quintillion times higher than bare fusion reactions. (A quintillion is a 1 followed by 18 zeroes.)
Researchers are not exactly sure why that’s happening, though they have some ideas and ways to test them. The electrons and defects within the material might partially shield repulsive electrostatic forces between deuterium nuclei, making it easier for them to get close together and fuse. Tuning the electronic structure, defects, and composition of materials could help make nuclear reactions happen more readily.
Prize honors discovery of altermagnetism as a third fundamental class of magnetism
One of Europe’s highest distinctions in condensed matter physics has been awarded for a discovery that is reshaping our understanding of magnetism: The 2026 Europhysics Prize of the European Physical Society (EPS) Condensed Matter Division goes to Professor Jairo Sinova of Johannes Gutenberg University Mainz (JGU), Dr. Libor Šmejkal and Professor Tomas Jungwirth for their discovery of altermagnetism—a previously unknown fundamental class of magnetism.
The prize recognizes their work establishing that nature hosts a third elementary form of collinear magnetism in addition to ferromagnetism and antiferromagnetism. The discovery overturns a century-old understanding of magnetic order and has opened an entirely new research field with major implications for quantum materials, condensed matter physics and future information technologies.
“This award recognizes a fundamental discovery that challenged one of the most established paradigms in condensed matter physics,” said Sinova, director of the Spin Phenomena Interdisciplinary Center (SPICE) at Mainz University. “Discovering that an entirely new magnetic phase had remained hidden for more than 100 years demonstrates that even the most mature scientific fields can still hold fundamental surprises.”