Phys.org Physics

• New microscope offers sharper view into momentum space

  Electrons are tiny and constantly in motion. How they behave in a crystal lattice determines key material properties: electrical conductivity, magnetism, or novel quantum effects. Anyone aiming to develop the information technologies of tomorrow must understand what electrons do. At Forschungszentrum Jülich, a new tool is now available for this purpose: a momentum microscope that was fully developed and built on site. "Internationally, we are currently seeing rapidly growing interest in this method," explains Dr. Christian Tusche from Forschungszentrum Jülich.

• Physicists break longstanding high-temperature superconductivity record at ambient pressure

  Researchers from the Texas Center for Superconductivity (TcSUH) and the department of physics at the University of Houston have broken the temperature record for superconductivity at ambient pressure—a breakthrough that could eventually lead to more efficient ways to generate, transmit, and store energy.

• Could a recently detected ultra-high-energy neutrino be linked to new physics?

  Neutrinos are extremely lightweight and electrically neutral particles that rarely interact with ordinary matter. Due to these rare interactions, neutrinos can travel across space almost entirely unaffected, carrying information about highly energetic cosmological events, such as exploding stars or supermassive black holes.

• Next-gen interferometric diffusing wave spectroscopy achieves 20x signal boost in cerebral blood flow monitoring

  Cerebral blood flow is essential for normal brain function and often perturbed in neurological disease. If one shines a source of coherent light on perfused tissue, the detected speckles, or "grains" of light fluctuate, or "dance," at a rate proportional to blood flow in the volume sampled by the light. In brain tissue, this concept can be harnessed to measure the cerebral blood flow index (CBFi).

• Researchers realize room-temperature two-dimensional multiferroic metal

  Multiferroic metals are materials that exhibit both electric polarization and magnetic order in the same crystal—a state known as multiferroicity. Because these properties coexist, they can interact through magnetoelectric (ME) coupling, allowing electric fields to influence magnetism.

• Inside the light: How invisible electric fields drive device luminescence

  Fleeting electron-hole pairs are giving scientists a new window into optimizing light-emitting devices (LEDs). Using quantum magnetic resonance, Osaka Metropolitan University researchers have discovered how shifting internal electric fields dictate whether these devices shine brightly or dimly. Their study is published in the journal Advanced Optical Materials.

• Quantum computers must overcome major technical hurdles before tackling quantum chemistry problems

  Although the potential applications of quantum computing are widespread, a new feasibility study suggests quantum computers still face major hurdles in solving quantum chemistry problems. The study, published in Physical Review B, evaluates what criteria are needed for a quantum advantage in searching for the ground state energy of molecules. The researchers attempt this feat using two different algorithms with differing strengths and weaknesses.

• Quantum dots generate entangled photon pairs on demand

  For the first time, researchers in China have demonstrated how quantum dots can be engineered to consistently generate pairs of entangled photons. By carefully tailoring the photonic environment surrounding a single quantum dot, the team showed that it is possible to produce highly correlated photon pairs with remarkable efficiency, potentially opening new opportunities for emerging quantum technologies. The work, led by Zhiliang Yuan at the Beijing Academy of Quantum Information Sciences, is reported in Nature Materials.

• Physicists observe rare nuclear isomer in ytterbium-150 for first time

  Nuclear isomers are crucial probes for studying the structure of nuclei. Unlike chemical isomers—which have the same chemical formula but different arrangements of atoms—nuclear isomers are nuclei that exist in a long-lived and relatively stable excited state.

• 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.