Phys.org Physics

• Quantum dots reveal entropy production, a key measure of nanoscale energy dissipation

  In order to build the computers and devices of tomorrow, we have to understand how they use energy today. That's harder than it sounds. Memory storage, information processing, and energy use in these technologies involve constant energy flow—systems never settle into thermodynamic balance. To complicate things further, one of the most precise ways to study these processes starts at the smallest scale: the quantum domain.

• How fast can a microlaser switch 'modes?' A simple rule reveals a power-law time scaling

  Modern technologies increasingly rely on light sources that can be reconfigured on demand. Think of microlasers that can quickly switch between different operating states—much like a car shifting gears—so that an optical chip can route signals, perform computations, or adapt to changing conditions in real time. The microlaser switching is not a smooth, leisurely process, but can be sudden and fast. Generally, nearly identical "candidate" lasing states compete with each other in a microcavity, and the laser may abruptly jump from one state to another when external conditions are tuned.

• Ordered 'supercrystal' could make lasers faster, smaller and more efficient

  An advance from Monash University could pave the way for faster, smaller, and more energy-efficient lasers and other light-based technologies. Engineers have developed a new type of perovskite material arranged into an ordered "supercrystal." In this structure, tiny packets of energy called excitons work together rather than individually, allowing the material to amplify light far more efficiently. The findings, published in Laser & Photonics Reviews, could have applications in communications, sensors, and computing, improving the performance of devices that rely on light, such as sensors in autonomous vehicles, medical imaging, or electronics.

• Topological antenna could pave the way for 6G networks

  Using ideas borrowed from topological photonics, researchers in Singapore, France and the US have designed a compact antenna capable of handling information-rich terahertz (THz) signals. Reporting their results in Nature Photonics, the team, led by Ranjan Singh at the University of Notre Dame, say that with further refinements, the design could help underpin future sixth-generation (6G) wireless networks, allowing data to be shared at unprecedented speeds.

• Light-based Ising computer runs at room temperature and stays stable for hours

  A team of researchers at Queen's University has developed a powerful new kind of computing machine that uses light to take on complex problems such as protein folding (for drug discovery) and number partitioning (for cryptography). Built from off-the-shelf components, it also operates at room temperature and remains remarkably stable while performing billions of operations per second. The research was published in Nature.

• Researchers demonstrate organic crystal emitting red light from UV and green from near-infrared

  Invisible light beyond the range of human vision plays a vital role in communication technologies, medical diagnostics, and optical sensing. Ultraviolet and near-infrared wavelengths are routinely used in these fields, yet detecting them directly often requires complex instrumentation.

• Broken inversion symmetry lets 3D crystals mimic 2D Ising superconductivity

  Two-dimensional (2D) materials, in general, allow the realization of unique quantum phenomena unattainable in the common three-dimensional (3D) world. A prime example is graphene. Transition metal dichalcogenides (TMDs) have a similar structure. Both can be stacked to form van der Waals heterostructures or can be exfoliated into single layers. But TMDs have an extra variety of excellent properties, including strong spin-orbit coupling and superconductivity.

• Quantum encryption method demonstrated at city-sized distances for the first time

  Concerns that quantum computers may start easily hacking into previously secure communications has motivated researchers to work on innovative new ways to encrypt information. One such method is quantum key distribution (QKD), a secure, quantum-based method in which eavesdropping attempts disrupt the quantum state, making unauthorized interception immediately detectable.

• Three-way quantum correlations fade exponentially with distance at any temperature, study shows

  The properties of a quantum material are driven by links between its electrons known as quantum correlations. A RIKEN researcher has shown mathematically that, at non-zero temperatures, these connections can only exist over very short distances when more than two particles are involved. This finding, now published in Physical Review X, sets a fundamental limit on just how "exotic" a quantum material can be under realistic, finite-temperature conditions.

• Quantum Twins simulator unveils 15,000 controllable quantum dots for materials research

  Researchers in Australia have unveiled the largest quantum simulation platform built to date, opening a new route to exploring the complex behavior of quantum materials at unprecedented scales.

• Study reveals microscopic origins of surface noise limiting diamond quantum sensors

  A new theoretical study led by researchers at the University of Chicago and Argonne National Laboratory has identified the microscopic mechanisms by which diamond surfaces affect the quantum coherence of nitrogen-vacancy (NV) centers—defects in diamond that underpin some of today's most sensitive quantum sensors. The study has appeared in Physical Review Materials and was selected to be an Editors' Suggestion paper.

• Extreme plasma acceleration in monster shocks offers new explanation for fast radio bursts

  In a new study published in Physical Review Letters, scientists have performed the first global simulations of monster shocks—some of the strongest shocks in the universe—revealing how these extreme events in magnetar magnetospheres could be responsible for producing fast radio bursts (FRBs).

• Scientists discover 'levitating' time crystals that you can hold in your hand

  Time crystals, a collection of particles that "tick"—or move back and forth in repeating cycles—were first theorized and then discovered about a decade ago. While scientists have yet to create commercial or industrial applications for this intriguing form of matter, these crystals hold great promise for advancing quantum computing and data storage, among other uses.

• Measuring time at the quantum level depends on material symmetry

  EPFL physicists have found a way to measure the time involved in quantum events and found it depends on the symmetry of the material. "The concept of time has troubled philosophers and physicists for thousands of years, and the advent of quantum mechanics has not simplified the problem," says Professor Hugo Dil, a physicist at EPFL. "The central problem is the general role of time in quantum mechanics, and especially the timescale associated with a quantum transition."

• Into the neutrino fog: The ghosts haunting our search for dark matter

  Ciaran O'Hare scribbles symbols using colored markers across his whiteboard like he's trying to solve a crime—or perhaps planning one. He bounces around the edges of the board, slowly filling it with sharp angles and curling letters. I watch on, and when he senses I'm losing track, he pauses intermittently, allowing my brain to catch up. Ciaran speaks with an easy to understand British inflection, but the language on the whiteboard might as well be hieroglyphics.

• Tuning topological superconductors into existence by adjusting the ratio of two elements

  Today's most powerful computers hit a wall when tackling certain problems, from designing new drugs to cracking encryption codes. Error-free quantum computers promise to overcome those challenges, but building them requires materials with exotic properties of topological superconductors that are incredibly difficult to produce. Now, researchers at the University of Chicago Pritzker School of Molecular Engineering (UChicago PME) and West Virginia University have found a way to tune these materials into existence by simply tweaking a chemical recipe, resulting in a change in many-electron interactions.

• When lasers cross: A brighter way to measure plasma

  Measuring conditions in volatile clouds of superheated gases known as plasmas is central to pursuing greater scientific understanding of how stars, nuclear detonations and fusion energy work. For decades, scientists have relied on a technique called Thomson scattering, which uses a single laser beam to scatter from plasma waves as a way to measure critical information such as plasma temperature, density and flow.

• VIP-2 experiment narrows the search for exotic physics beyond the Pauli exclusion principle

  The Pauli exclusion principle is a cornerstone of the Standard Model of particle physics and is essential for the structure and stability of matter. Now an international collaboration of physicists has carried out one of the most stringent experimental tests to date of this foundational rule of quantum physics and has found no evidence of its violation. Using the VIP-2 experiment, the team has set the strongest limits so far for possible violations involving electrons in atomic systems, significantly constraining a range of speculative theories beyond the Standard Model, including those that suggest electrons have internal structure, and so-called "Quon models." Their experiment was reported in Scientific Reports in November 2025.

• AI-powered compressed imaging system developed for high-speed scenes

  A research team from the Xi'an Institute of Optics and Precision Mechanics (XIOPM) of the Chinese Academy of Sciences, along with collaborators from the Institute National de la Recherche Scientifique, Canada, and Northwest University, has developed a single-shot compressed upconversion photoluminescence lifetime imaging (sCUPLI) system for high-speed imaging.

• High-entropy garnet crystal enables enhanced 2.8 μm mid-infrared laser performance

  Recently, a research team from the Hefei Institutes of Physical Science of the Chinese Academy of Sciences successfully grew a high-entropy garnet-structured oxide crystal and achieved enhanced laser performance at the 2.8 μm wavelength band. By introducing a high-entropy design into a garnet crystal system, the team obtained a wide emission band near 2.8 μm and continuous-wave laser output with improved average power and beam quality, demonstrating the material's strong potential as a high-performance gain medium for mid-infrared ultrashort-pulse lasers.

• Surgery for quantum bits: Bit-flip errors corrected during superconducting qubit operations

  Quantum computers hold great promise for exciting applications in the future, but for now they keep presenting physicists and engineers with a series of challenges and conundrums. One of them relates to decoherence and the errors that result from it: bit flips and phase flips. Such errors mean that the logical unit of a quantum computer, the qubit, can suddenly and unpredictably change its state from "0" to "1," or that the relative phase of a superposition state can jump from positive to negative.

• How superconductivity arises: New insights from moiré materials

  How exactly unconventional superconductivity arises is one of the central questions of modern solid-state physics. A new study published in the journal Nature provides crucial insights into this question. For the first time, an international research team was able to demonstrate a direct microscopic connection between a strongly correlated normal state and superconductivity in so-called moiré materials. In the long term, these findings could contribute to the development of new quantum materials and superconductors for future quantum technologies.

• Electron-phonon 'surfing' could help stabilize quantum hardware, nanowire tests suggest

  That low-frequency fuzz that can bedevil cellphone calls has to do with how electrons move through and interact in materials at the smallest scale. The electronic flicker noise is often caused by interruptions in the flow of electrons by various scattering processes in the metals that conduct them.

• Glimpsing the quantum vacuum: Particle spin correlations offer insight into how visible matter emerges from 'nothing'

  Scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have uncovered experimental evidence that particles of matter emerging from energetic subatomic smashups retain a key feature of virtual particles that exist only fleetingly in the quantum vacuum. The finding offers a new way to explore how the vacuum—once thought of as empty space—provides important ingredients needed to transform virtual "nothingness" into the matter that makes up our world.

• From cryogenic to red-hot: Optical temperature sensing from 77 K to 873 K

  An international collaboration involving researchers from the University of Innsbruck has developed a novel luminescent material that enables particularly robust and precise optical temperature sensing across an exceptionally broad temperature range.