Phys.org Physics

• Observing the positronium beam as a quantum matter wave for the first time

  One of the discoveries that fundamentally distinguished the emerging field of quantum physics from classical physics was the observation that matter behaves differently at the smallest scales. A key finding was wave-particle duality, the revelation that particles can exhibit wave-like properties.

• Quantum 'alchemy' made feasible with excitons

  What if you could create new materials just by shining a light at them? To most, this sounds like science fiction or alchemy, but to physicists investigating the burgeoning field of Floquet engineering, this is the goal. With a periodic drive, like light, scientists can "dress up" the electronic structure of any material, altering its fundamental properties—such as turning a simple semiconductor into a superconductor.

• Bioinspired phototransistor achieves high-sensitivity detection of low-contrast targets

  Drawing inspiration from the remarkable adaptability of the human eye, researchers from the Institute of Metal Research (IMR) of the Chinese Academy of Sciences have developed a novel phototransistor with tunable sensitivity.

• New class of strong magnets uses earth-abundant elements, avoids rare-earth metals

  Georgetown University researchers have discovered a new class of strong magnets that do not rely on rare-earth or precious metals—a breakthrough that could significantly advance clean energy technologies and consumer electronics such as motors, robotics, MRI machines, data storage and smart phones.

• Detecting single-electron qubits: Microwaves could probe quantum states above liquid helium

  One intriguing method that could be used to form the qubits needed for quantum computers involves electrons hovering above liquid helium. But it wasn't clear how data in this form could be read easily.

• The world's first room-temperature continuous-wave UV-B laser diode on a sapphire substrate

  Ultraviolet-B (UV-B) semiconductor lasers are highly sought for medical, biotechnology, and precision manufacturing applications; however, previous UV-B laser diodes were limited to pulsed operation or required cryogenic cooling, making continuous room-temperature operation unattainable.

• Imaging technique captures ultrafast electron and atom dynamics in chemical reactions

  During chemical reactions, atoms in the reacting substances break their bonds and re-arrange, forming different chemical products. This process entails the movement of both electrons (i.e., negatively charged particles) and nuclei (i.e., the positively charged central parts of atoms). Valence electrons are shared and re-arranged between different atoms, creating new bonds.

• Honeycomb lattice sweetens quantum materials development

  Researchers at the Department of Energy's Oak Ridge National Laboratory are pioneering the design and synthesis of quantum materials, which are central to discovery science involving synergies with quantum computation. These innovative materials, including magnetic compounds with honeycomb-patterned lattices, have the potential to host states of matter with exotic behavior.

• Understanding the unusual chirality-driven anomalous Hall effect via scattering theory

  A new framework for understanding the nonmonotonic temperature dependence and sign reversal of the chirality-related anomalous Hall effect in highly conductive metals has been developed by scientists at Science Tokyo. This framework provides a clear picture of the unusual temperature dependence of chirality-driven transport phenomena, forming a foundation for the rational design of next-generation spintronic devices and magnetic quantum materials.

• X-ray four-wave mixing captures elusive electron interactions inside atoms and molecules

  Scientists at the X-ray free-electron laser SwissFEL have realized a long-pursued experimental goal in physics: to show how electrons dance together. The technique, known as X-ray four-wave mixing, opens a new way to see how energy and information flow within atoms and molecules. In the future, it could illuminate how quantum information is stored and lost, eventually aiding the design of more error-tolerant quantum devices. The findings are reported in Nature.

• New spectroscopic method reveals ion's complex nuclear structure

  Different atoms and ions possess characteristic energy levels. Like a fingerprint, they are unique for each species. Among them, the atomic ion 173Yb+ has attracted growing interest because of its particularly rich energy structure, which is promising for applications in quantum technologies and searches for so-called new physics. On the flip side, the complex structure that makes 173Yb+ interesting has long prevented detailed investigations of this ion.

• New microscopy technique preserves the cell's natural conditions

  Researchers at Istituto Italiano di Tecnologia (IIT-Italian Institute of Technology) have developed an innovative microscopy technique capable of improving the observation of living cells. The study, published in Optics Letters, paves the way for a more in-depth analysis of numerous biological processes without the need for contrast agents. The next step will be to enhance this technique using artificial intelligence, opening the door to a new generation of optical microscopy methods capable of combining direct imaging with innovative molecular information.

• Wormholes may not exist—we've found they reveal something deeper about time and the universe

  Wormholes are often imagined as tunnels through space or time—shortcuts across the universe. But this image rests on a misunderstanding of work by physicists Albert Einstein and Nathan Rosen.

• Efficient cooling method could enable chip-based quantum computers

  Quantum computers could rapidly solve complex problems that would take the most powerful classical supercomputers decades to unravel. But they'll need to be large and stable enough to efficiently perform operations. To meet this challenge, researchers at MIT and elsewhere are developing quantum computers based on ultra-compact photonic chips. These chip-based systems offer a scalable alternative to some existing quantum computers, which rely on bulky optical equipment.

• Overcoming symmetry limits in photovoltaics through surface engineering

  A recent study carried out by researchers from EHU, the Materials Physics Center, nanoGUNE, and DIPC introduces a novel approach to solar energy conversion and spintronics. The work tackles a long-standing limitation in the bulk photovoltaic effect—the need for non-centrosymmetric crystals—by demonstrating that even perfectly symmetric materials can generate significant photocurrents through engineered surface electronic states. This discovery opens new pathways for designing efficient light-to-electricity conversion systems and ultrafast spintronic devices.

• Turning crystal flaws into quantum highways: A new route towards scalable solid-state qubits

  Building large-scale quantum technologies requires reliable ways to connect individual quantum bits (qubits) without destroying their fragile quantum states. In a new theoretical study, published in npj Computational Materials, researchers show that crystal dislocations—line defects long regarded as imperfections—can instead serve as powerful building blocks for quantum interconnects.

• Slowing down muon decay with short laser pulses

  Muons are unstable subatomic particles that spontaneously and rapidly transform into other particles via a process known as electroweak decay. Altering the speed with which muons decay into other particles was so far deemed a challenging quest, requiring very strong electromagnetic fields that cannot be produced in conventional laboratory settings.

• Temporal anti-parity–time symmetry offers new way to steer energy through systems

  The movement of waves, patterns that carry sound, light or heat, through materials has been widely studied by physicists, as it has implications for the development of numerous modern technologies. In several materials, the movement of waves depends on a physical property known as parity-time (PT) symmetry, which combines mirror-like spatial symmetry with a symmetry in a system's behavior when time runs forward and backwards.

• Tuning spin waves—using commercially available devices at room temperature

  Physicist Davide Bossini from the University of Konstanz has recently demonstrated how to change the frequency of the collective magnetic oscillations of a material by up to 40%—using commercially available devices at room temperature.

• Neutral-atom arrays, a rapidly emerging quantum computing platform, get a boost from researchers

  For quantum computers to outperform their classical counterparts, they need more quantum bits, or qubits. State-of-the-art quantum computers have around 1,000 qubits. Columbia physicists Sebastian Will and Nanfang Yu have their sights set much higher.

• Quantum simulator reveals how vibrations steer energy flow in molecules

  Researchers led by Rice University's Guido Pagano used a specialized quantum device to simulate a vibrating molecule and track how energy moves within it. The work, published Dec. 5 in Nature Communications, could improve understanding of basic mechanisms behind phenomena such as photosynthesis and solar energy conversion.

• Physics of foam strangely resembles AI training

  Foams are everywhere: soap suds, shaving cream, whipped toppings and food emulsions like mayonnaise. For decades, scientists believed that foams behave like glass, their microscopic components trapped in static, disordered configurations.

• New state of matter discovered in a quantum material

  At TU Wien, researchers have discovered a state in a quantum material that had previously been considered impossible. The definition of topological states should be generalized.

• Taming heat: Novel solution enables unprecedented control of heat conduction

  Prof. Gal Shmuel of the Faculty of Mechanical Engineering at the Technion—Israel Institute of Technology has developed an innovative approach that enables precise control of heat conduction in ways that do not occur naturally.

• Magnetic fields slow carbon migration in iron by altering energy barriers, study shows

  Professor Dallas Trinkle and colleagues have provided the first quantitative explanation for how magnetic fields slow carbon atom movement through iron, a phenomenon first observed in the 1970s but never fully understood. Published in Physical Review Letters, their computer simulations reveal that magnetic field alignment changes the energy barriers between atomic "cages," offering potential pathways to reduce the energy costs and CO2 emissions associated with steel processing.