Phys.org Physics

• Bioinspired event camera tracks full vibration trajectory using geometry

  Researchers at University of Tsukuba have developed a noncontact vibration measurement method using an event camera, a sensing technology inspired by biological vision. By applying geometric analysis to event-stream data, the team succeeded in reconstructing vibrations—an achievement that had posed substantial challenges using an event camera.

• Local droplet etching yields more symmetric quantum dots for integrated photonics

  Light-based quantum technologies, such as quantum communication and photonic quantum computing, require reliable sources of individual photons and, ideally, pairs of entangled photons. Semiconductor quantum dots are promising candidates for this purpose. These nanostructures have electrical conductivity between that of insulators and conductors and are capable of confining electrons and holes. This property causes them to emit light at well-defined frequencies when excited by a laser.

• Asymmetric spin torque unlocks deterministic control of antiferromagnetic memory

  A research team led by Prof. Shao Dingfu from the Hefei Institutes of Physical Science, Chinese Academy of Sciences, has proposed a universal mechanism that enables deterministic electrical control of collinear antiferromagnets—overcoming a long-standing bottleneck in antiferromagnetic spintronics. The study is published in Physical Review Letters.

• Palm-sized superconducting magnet achieves 42 tesla, rivaling the world's biggest

  When we think of powerful magnets used in particle accelerators or for NMR (nuclear magnetic resonance), we often envision bulky machines, sometimes the size of buildings. But in an extraordinary breakthrough for physics, scientists at ETH Zurich have created magnets that are small enough to fit in the palm of your hand yet powerful enough to rival some of the world's most powerful magnets.

• Fiber setup compresses mid-infrared pulses to 187 femtoseconds using just 80 watts

  Ultrashort mid-infrared (mid-IR) laser pulses are essential for applications such as molecular spectroscopy, nonlinear microscopy, and biomedical imaging, but their generation often relies on complex and power-intensive systems that are difficult to implement outside of specialized laboratories. These systems usually require high pump powers, elaborate optical setups, and precise alignment, which can limit their widespread adoption and practical use in everyday research and clinical settings.

• Stacked quantum materials enable precise spin control without external magnetic fields

  Spintronics—a technology that harnesses the electron's magnetic quantum states to carry information—could pave the way for a new generation of ultra-energy-efficient electronics. Yet a major challenge has been the ability to control these delicate quantum properties with sufficient precision for practical applications. By combining different quantum materials, researchers at Chalmers University of Technology have now taken a decisive step forward, achieving unprecedented control over spin phenomena. The advance opens the door to next-generation low-power data processing and memory technologies.

• Simulations suggest a breakthrough in understanding how turbulence develops

  A new study revisits a century-old question about how turbulence starts. The findings could potentially influence not only aircraft engineering but even the design of mechanical heart valves, and treatment of heart disease. The study is published in Scientific Reports.

• Fluid simulation at unprecedented scale provides toolkit for fundamental physics and applied fluid engineering

  What governs the speed at which raindrops fall, sediment settles in river estuaries, and matter is ejected during a supernova? These questions circle around one, deceitfully simple factor: the rate at which a fluid filled with particles mixes with a particle-free one. Raindrops travel from one layer of air to another; sediment falls from river to seawater, and ejecta travels from the exploding star through the surrounding dust cloud. The same principle dictates sediment mixing in rising smoke, dust storms, nuclear explosions, hydrocarbon refining, metal smelting, wastewater treatment, and more.

• Twisted bilayer photonic crystals dynamically tune light's handedness

  Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have created a chip-scale device that can dynamically control the "handedness" of light as it passes through—also known as its optical chirality—with a simple twist of two specially designed photonic crystals. The study is published in the journal Optica.

• Photonic 'ski jumps' efficiently beam light into free space

  Photonic chips use light to process data instead of electricity, enabling faster communication speeds and greater bandwidth. Most of that light typically stays on the chip, trapped in optical wires, and is difficult to transmit to the outside world in an efficient manner.

• Acoustic driving enables controlled condensation of light and matter on chip

  An international research team led by Alexander Kuznetsov at the Paul Drude Institute for Solid State Electronics (PDI) in Berlin has demonstrated a fundamentally new way to control the condensation of hybrid light-matter particles. Using coherent acoustic driving to dynamically reshape the energy landscape of a semiconductor microcavity, the researchers achieved deterministic steering of a macroscopic quantum state into its lowest energy configuration.

• Researchers mix X-rays and optical light to track speedy electrons in materials

  To unlock materials of the future, including better photocatalysts or light-switchable superconductors, researchers need to understand how the valence electrons within materials respond to light at the atomic scale. Materials are made of atoms, and an atom's outer electrons, or valence electrons, are responsible for chemical bonding as well as a material's thermal, magnetic, and electronic properties.

• Scalable quantum batteries can charge faster than their classical counterparts

  Over the past decades, energy engineers have developed increasingly advanced battery technologies that can store more energy, charge faster and maintain their performance for longer. In recent years, some researchers have also started exploring the potential of quantum batteries, devices that can store energy leveraging quantum mechanical effects.

• Watching quantum behavior in action: MagnetoARPES reveals time-reversal symmetry breaking in a kagome superconductor

  Electron movement and structures described in quantum physics allow researchers to better understand how and why materials like superconductors behave as they do. Rice University researchers Jianwei Huang and Ming Yi have developed a new capability, magnetoARPES, building on angle-resolved photoemission spectroscopy (ARPES) that allows researchers to study quantum behaviors they have been unable to resolve using ARPES alone. The work has been published in Nature Physics.

• Ultrafast computing: Light-driven logic tops 10 terahertz in WS₂

  The future for our computers will literally be at the speed of light. Extremely short light pulses can perform ultrafast logical operations: these are the findings of a study recently published in the journal Nature Photonics. The study represents an important step toward developing a new generation of information processing technologies, potentially hundreds of times faster than what we have at present.

• Chemical shifts help track molecules breaking apart in real time

  When molecules fall apart, their electric charge doesn't stay put—it rearranges as bonds stretch and break. An international team of scientists has now tracked these ultrafast changes in the small molecule fluoromethane (CH₃F). It was the first time that the Small Quantum Systems (SQS) instrument at European XFEL could deliver detailed insights into transient states during chemical reactions. The research is published in the journal Physical Review X.

• Unexpected magnetic response in gold and silver atomic contacts contradicts previous theoretical predictions

  Researchers from the Department of Physics and the University Institute of Materials at the University of Alicante (UA) and the Low Temperature and High Magnetic Field Laboratory at the Autonomous University of Madrid (UAM) have succeeded in measuring, for the first time, the electrical conductance of gold and silver atomic contacts subjected to extreme magnetic fields of up to 20 teslas, an intensity equivalent to 400,000 times Earth's magnetic field.

• 3D-printed photonic lanterns combine up to 37 multimode lasers into one fiber

  Researchers have developed a microscopic 3D-printed optical device that can efficiently combine light from dozens of small semiconductor lasers into a single multimode optical fiber with very low loss. The team demonstrated photonic lanterns that multiplex 7, 19, and 37 multimode VCSEL lasers directly into a fiber while preserving brightness and easing alignment constraints. By enabling scalable incoherent beam combining of many multimode lasers, the technology could simplify and improve high-power laser systems, optical communications, and other photonic applications where efficiently delivering large optical power through fibers is critical.

• Scientists control 'free-flowing' electric currents with light

  By controlling magnetic fields using light, a team of researchers led by NTU scientists has solved a long-standing challenge to precisely direct electric currents produced by quantum materials. Their findings unlock new avenues for controlling the flow of electricity through such materials and could herald the age of energy-efficient quantum computing devices. The research is published in Nature in January.

• Understanding how wind moves pollen can guide urban planning decisions about green spaces

  Due to climate change, plants' pollination season has been growing longer and longer. As a result, people are exposed to allergens for extended periods each year, raising a major public health concern. Researchers from Embry‑Riddle Aeronautical University, the University of Rouen Normandy and the University of Lille have developed an advanced computational model of outdoor airflow through trees. They recently used it to study how a tree's geometry affects the dynamics and dispersion of its airborne pollen grains. The work appears in Physics of Fluids.

• Precisely measuring quantum signals in large spin ensembles

  Quantum mechanical effects are known to be easily disrupted by disturbances from the surrounding environment, commonly referred to as noise. To minimize these disturbances, physicists often study these effects in small and carefully controlled systems, in which environmental noise can be minimized.

• How does snow gather on a roof? Simulation considers turbulence alongside snowflake size

  No two snowflakes may be the same, but models that fail to take these variations into consideration often fall short when calculating the way snow accumulates on roofs. In Physics of Fluids, researchers from Harbin Institute of Technology in China modeled the way snow gathers on a roof based on snowflake size and distribution.

• Study shows spiral sound can shift sideways

  A new University of Mississippi study shows that some sound waves don't just move forward—they also move slightly to the side. Understanding this movement could help researchers develop more precise acoustic tools. Likun Zhang, associate professor of physics and astronomy and senior scientist at the National Center for Physical Acoustics, published his team's study on the behavior of spiral sound waves in Physical Review Letters.

• Miniature laser technology could bring lab testing into your home

  A research team at Chalmers University of Technology, Sweden, has developed new laser technology that could lead to tiny, cost-effective biosensors. The sensors integrate lasers and optics together on a centimeter-sized chip, which could move testing from hospitals to patients' homes. This, in turn, would free up hospital beds and reduce visits to clinics.

• In search of a room-temperature superconductor, scientists present a research agenda

  The search for materials that can conduct electricity at room temperature without losing energy is one of the greatest and most consequential challenges of modern physics: loss-free power transmission, more efficient motors and generators, more powerful quantum computers, cheaper MRI devices. Hardly any other material discovery has the potential to change so many areas of technology and everyday life at the same time.