Phys.org Physics

• New photonic chips passively convert laser light into multiple colors on demand

  Over the past several decades, researchers have been making rapid progress in harnessing light to enable all sorts of scientific and industrial applications. From creating stupendously accurate clocks to processing the petabytes of information zipping through data centers, the demand for turnkey technologies that can reliably generate and manipulate light has become a global market worth hundreds of billions of dollars.

• Raman quantum memory demonstrates near-unity performance

  Over the past decades, quantum physicists and engineers have developed numerous technologies that harness the principles of quantum mechanics to push the boundaries of classical information science. Among these advances, quantum memories stand out as promising devices for storing and retrieving quantum information encoded in light or other physical carriers.

• Electrical control of spin currents in graphene via ferroelectric switching achieved

  A collaborative European research team led by physicists from Slovak Academy of Sciences has theorized a new approach to control spin currents in graphene by coupling it to a ferroelectric In2Se3 monolayer. Using first-principles and tight-binding simulations, the researcher showed that the ferroelectric switching of In2Se3 can reverse the direction of the spin current in graphene acting as an electrical spin switch. This discovery offers a novel pathway toward energy-efficient, nonvolatile, and magnet-free spintronic devices, marking a key step toward the fabrication of next-generation spin-based logic and memory systems to control spin textures.

• HD⁺ ions cooled to 18 mK yield most precise vibrational-rotational spectra to date

  A research team from the Innovation Academy for Precision Measurement Science and Technology (APM) of the Chinese Academy of Sciences has made significant progress in precisely measuring the vibrational-rotational spectra of hydrogen molecular ions (HD⁺).

• Reading a quantum clock costs more energy than running it, study finds

  A study led by the University of Oxford has identified a surprising source of entropy in quantum timekeeping—the act of measurement itself. In a study published in Physical Review Letters, scientists demonstrate that the energy cost of "reading" a quantum clock far outweighs the cost of running it, with implications for the design of future quantum technologies.

• Controlling triple quantum dots in a zinc oxide semiconductor

  Quantum computers have the potential to solve certain calculations exponentially faster than a classic computer could, but more research is desperately needed to make their practical use a reality. Quantum computers use a basic unit of information called quantum bits (qubits) to run—like how classical computers use a binary system of 0s and 1s, but with many more possibilities.

• How sound and light act alike—and not—at the smallest scale

  A world-famous light experiment from 1801 has now been carried out with sound for the first time. Research by physicists in Leiden has produced new insights that could be applied in 5G devices and the emerging field of quantum acoustics. The study is published in the journal Optics Letters.

• Heavy atomic nuclei are not as symmetric as previously thought, physicists find

  Many heavy atomic nuclei are shaped more or less like squashed rugby balls than fully inflated ones, according to a theoretical study by RIKEN nuclear physicists published in The European Physical Journal A. This unexpected finding overturns the consensus held for more than half a century.

• Physicists unveil system to solve long-standing barrier to new generation of supercomputers

  The dream of creating game-changing quantum computers—supermachines that encode information in single atoms rather than conventional bits—has been hampered by the formidable challenge known as quantum error correction.

• Reactor-grade fusion plasma: First high-precision measurement of potential dynamics

  Nuclear fusion, which operates on the same principle that powers the sun, is expected to become a sustainable energy source for the future. To achieve fusion power generation, it is essential to confine plasma at temperatures exceeding one hundred million degrees using a magnetic field and to maintain this high-energy state stably.

• Unified model may explain vibrational anomalies in solids

  Phonons are sound particles or quantized vibrations of atoms in solid materials. The Debye model, a theory introduced by physicist Peter Debye in 1912, describes the contribution of phonons to the specific heat of materials and explains why the amount of heat required to raise the temperature of solids drops sharply at low temperatures.

• Tabletop particle accelerator could transform medicine and materials science

  A particle accelerator that produces intense X-rays could be squeezed into a device that fits on a table, my colleagues and I have found in a new research project.

• Ultrafast light-driven electron slide discovered

  When an intense laser pulse hits a stationary electron, it performs a trembling motion at the frequency of the light field. However, this motion dies down after the pulse, and the electron comes to rest again at its original location. If, however, the light field changes its strength along the electron's trajectory, the electron builds up an additional drift motion with each oscillation, which it retains even after the pulse. The spatial light intensity acts like a slope that the electron slides down.

• Ultrafast electron diffraction captures atomic layers twisting in response to light

  A pulse of light sets the tempo in the material. Atoms in a crystalline sheet just a few atoms thick begin to move—not randomly, but in a coordinated rhythm, twisting and untwisting in sync like dancers following a beat.

• String theory: Scientists are trying new ways to verify the idea that could unite all of physics

  In 1980, Stephen Hawking gave his first lecture as Lucasian Professor at the University of Cambridge. The lecture was called "Is the end in sight for theoretical physics?"

• Optimal scaling for magic state distillation in quantum computing achieved

  Researchers have demonstrated that the theoretically optimal scaling for magic state distillation—a critical bottleneck in fault-tolerant quantum computing—is achievable for qubits, improving on the previous best result by reaching a scaling exponent of exactly zero.

• Researchers validate measurement-protection quantum key distribution

  Korean researchers have successfully established a measurement protection (MP) theory that enables stable quantum key distribution (QKD) without the need for measurement correction of quantum states, and experimentally verified it.

• Q&A: Chiral phonons research offers new ways to control materials

  The rapidly growing field of research on chiral phonons is giving researchers new insights into the fundamental behaviors and structures of materials. The chirality of phonons could pave the way for new methods to control material properties and to encode information at the quantum level, which has implications for, among other areas, quantum technologies, electronics, energy transport, and sensor technology.

• First full simulation of 50-qubit universal quantum computer achieved

  A research team at the Jülich Supercomputing Center, together with experts from NVIDIA, has set a new record in quantum simulation: for the first time, a universal quantum computer with 50 qubits has been fully simulated—a feat achieved on Europe's first exascale supercomputer, JUPITER, inaugurated at Forschungszentrum Jülich in September.

• Metasurfaces show promise in boosting AR image clarity and brightness

  Researchers have designed and demonstrated a new optical component that could significantly enhance the brightness and image quality of augmented reality (AR) glasses. The advance brings AR glasses a step closer to becoming as commonplace and useful as today's smartphones.

• A century-old mixing puzzle: AI helps predict and understand viscous fingering

  Viscous fingering occurs when a thinner fluid pushes a thicker, more viscous fluid in a porous medium, like underground rock, creating unpredictable, finger-like patterns. For decades, this intricate dance between fluids has been a major headache in critical sectors like enhanced oil recovery, CO2 sequestration, and groundwater remediation. Predicting and controlling these "fingers" has remained an elusive goal for scientists, largely due to the sheer complexity of the fluid dynamics involved.

• Non-harmonic two-color femtosecond lasers achieve 1,000-fold enhancement of white-light output in water

  Scientists at Japan's Institute for Molecular Science have achieved a 1,000-fold enhancement in white-light generation inside water by using non-harmonic two-color femtosecond laser excitation. This previously unexplored approach in liquids unlocks new nonlinear optical pathways, enabling a dramatic boost in supercontinuum generation. The breakthrough lays a foundation for next-generation bioimaging, aqueous-phase spectroscopy, and attosecond science in water.

• On-chip cryptographic protocol lets quantum computers self-verify results amid hardware noise

  Quantum computers, machines that process information leveraging quantum mechanical effects, could outperform classical computers on some optimization tasks and computations. Despite their potential, quantum computers are known to be prone to errors and their ability to perform computations is easily influenced by noise.

• Developers and expert users benchmark three leading open-source thermal conductivity calculation packages

  Mechanical Engineering Professor Alan McGaughey of Carnegie Mellon University recently coordinated the Phonon Olympics, bringing together developers and expert users to benchmark three leading open-source thermal conductivity calculation packages.

• Harnessing intricate, self-organized plasma patterns to destroy PFAS

  Increasing the surface area when plasma and water interact could help scale up a technology that destroys contaminants such as PFAS, detergents and microbial contaminants in drinking water, new research from the University of Michigan shows.