Phys.org Physics

• Strong Field Spin-Boson model revises how intense lasers drive electrons in dense matter

  A team of physicists from the University of Ottawa have developed a new theoretical model that shines new light on how scientists understand the way lasers interact with dense matter, such as solids and liquids. This could unlock advances in ultrafast physics and next-generation technology.

• Off-the-shelf components enable deployment-ready quantum entanglement source

  Efficient generation and reliable distribution of quantum entangled states is crucial for emerging quantum applications, including quantum key distribution (QKDs). However, conventional polarization-based entanglement states are not stable over long fiber networks. While time-bin entanglement offers a promising alternative, it requires complex infrastructure. In this study, researchers explore how stable time-bin entangled states can be generated and distributed using commercially available components, paving the way for practical quantum communication networks.

• A smart fluid that can be reconfigured with temperature

  Imagine a "smart fluid" whose internal structure can be rearranged just by changing temperature. In a new study published in Matter, researchers report a way to overcome a long-standing limitation in a class of "smart fluids" called nematic liquid crystal microcolloids, allowing for reconfigurable self-assembly of micrometer-sized particles dispersed in a nematic liquid crystal host.

• Specially engineered crystal reveals magnetism with quantum potential

  Researchers at the Department of Energy's Oak Ridge National Laboratory, working with international partners, have uncovered surprising behavior in a specially engineered crystal. Composed of tantalum, tungsten and selenium—elements often studied for their potential in advanced electronics—the crystal demonstrates an unexpected atomic arrangement that hints at novel applications in spin-based electronics and quantum materials.

• Physicists observe polaron formation for the first time

  When an electron travels through a polar crystalline solid, its negative charge attracts the positively charged atomic cores, causing the surrounding crystal lattice to deform. The electron and lattice distortion then move together through the material—like a single object. Physicists call these quasiparticles polarons. A team led by Professor Jochen Feldmann from LMU has succeeded in tracking the extremely brief formation process of this object for the first time, using an ultrafast imaging method.

• Plasma rotation simulations could help fusion reactors survive decades of use

  Scientists have long seen a puzzling pattern in tokamaks, the doughnut-shaped machines that could one day reliably generate electricity from fusing atoms. When plasma particles escape the core of the magnetic fields that hold the plasma in its doughnut shape, they stream down toward the exhaust system, known as the divertor. There, plasma particles strike metal plates, cool down and bounce back. (The returning atoms help fuel the fusion reaction.) But experiments consistently show that far more particles hit the inner divertor target than the outer one.

• New amplifier design promises less noise, more gain for quantum computers

  The low-noise, high-gain properties needed for high-performance quantum computing can be realized in a microwave photonic circuit device called a Josephson traveling-wave parametric amplifier (JTWPA), RIKEN researchers have shown experimentally. This advance stands to speed up development of superconducting quantum computer systems at the 100-qubit scale. The work is published in the journal Physical Review Applied.

• Proton's width measured to unparalleled precision, narrowing the path to new physics

  Physicists in Germany have carried out the most accurate measurement to date of the width of the proton. By examining a previously unexplored energy-level transition in the hydrogen atom, Lothar Maisenbacher and colleagues at the Max Planck Institute of Quantum Optics have shown that the Standard Model continues to hold up under extraordinarily tight scrutiny, leaving even less room than before for rival theories that contradict our best understanding of how the universe behaves. The research has been published in Nature.

• Quantum sensor research advances the pursuit of dark matter

  Researchers at the Department of Energy's Oak Ridge National Laboratory are helping to pave a path for the eventual discovery of dark matter. With new approaches to measurement in the quantum realm, using quantum optical sensing techniques, ORNL scientists are developing the methods required to achieve sight beyond sight—and detect this mysterious, invisible, yet seemingly ubiquitous substance.

• Silicon quantum processor detects single-qubit errors while preserving entanglement

  Quantum computers are alternative computing devices that process information, leveraging quantum mechanical effects, such as entanglement between different particles. Entanglement establishes a link between particles that allows them to share states in such a way that measuring one particle instantly affects the others, irrespective of the distance between them.

• Optical switch protocol verifies entangled quantum states in real time without destroying them

  The fragility and laws of quantum physics generally make the characterization of quantum systems time‑consuming. Furthermore, when a quantum system is measured, it is destroyed in the process. A breakthrough by researchers at the University of Vienna demonstrates a novel method for quantum state certification that efficiently verifies entangled quantum states in real time without destroying all available states—a decisive step forward in the development of robust quantum computers and quantum networks.

• Using light to probe fractional charges in a fractional Chern insulator

  In some quantum materials, which are materials governed by quantum mechanical effects, interactions between charged particles (i.e., electrons) can prompt the creation of quasiparticles called anyons, which carry only a fraction of an electron's charge (i.e., fractional charge) and fractional quantum statistics.

• Physicists explain the exceptional energy-harvesting efficiency of perovskites

  Despite being riddled with impurities and defects, solution-processed lead-halide perovskites are surprisingly efficient at converting solar energy into electricity. Their efficiency is approaching that of silicon-based solar cells, the industry standard. In a new study published in Nature Communications, physicists at the Institute of Science and Technology Austria (ISTA) present a comprehensive explanation of the mechanism behind perovskite efficiency that has long perplexed researchers.

• Strong correlations and superconductivity observed in a supermoiré lattice

  Two or more graphene layers that are stacked with a small twist angle in relation to each other form a so-called moiré lattice. This characteristic pattern influences the movement of electrons inside materials, which can give rise to strongly correlated states, such as superconductivity.

• Quantum research in two ways: From proving someone's location to simulating financial markets

  Quantum physics may sound abstract, but Ph.D. candidates Kirsten Kanneworff and David Dechant show that quantum research can also be very concrete. Together, they are investigating how quantum technology can change the world. While Kanneworff worked in the lab to study how quantum optics can be used to prove someone's location, Dechant focused on quantum computing for dynamic systems, such as the financial world. The two researchers are defending their doctoral theses this week.

• The IceCube experiment is ready to uncover more secrets of the universe

  The name "IceCube" not only serves as the title of the experiment, but also describes its appearance. Embedded in the transparent ice of the South Pole, a three-dimensional grid of more than 5,000 extremely sensitive light sensors forms a giant cube with a volume of one cubic kilometer. This unique arrangement serves as an observatory for detecting neutrinos, the most difficult elementary particles to detect.

• Hologram processing method boosts 3D image depth of focus fivefold

  Researchers from the University of Tartu Institute of Physics have developed a novel method for enhancing the quality of three-dimensional images by increasing the depth of focus in holograms fivefold after recording, using computational imaging techniques. The technology enables improved performance of 3D holographic microscopy under challenging imaging conditions and facilitates the study of complex biological structures.

• Time crystals could become accurate and efficient timekeepers

  Time crystals could one day provide a reliable foundation for ultra-precise quantum clocks, new mathematical analysis has revealed. Published in Physical Review Letters, the research was led by Ludmila Viotti at the Abdus Salam International Center for Theoretical Physics in Italy. The team shows that these exotic systems could, in principle, offer higher timekeeping precision than more conventional designs, which rely on external excitations to generate reliably repeating oscillations.

• IceCube upgrade adds six deep sensor strings to detect lower-energy neutrinos

  Since 2010, the IceCube Observatory at the Amundsen-Scott South Pole Station has been delivering groundbreaking measurements of high-energy cosmic neutrinos. It consists of many detectors embedded in a volume of Antarctic ice measuring approximately one cubic kilometer. IceCube has now been upgraded with new optical modules to enable it to measure lower-energy neutrinos as well. Researchers at the Karlsruhe Institute of Technology (KIT) made a significant contribution to this expansion.

• X-ray platform images plasma instability for fusion energy and astrophysics

  Harnessing the power of the sun holds the promise of providing future societies with energy abundance. To make this a reality, fusion researchers need to address many technological challenges. For example, fusion reactions occur within a superheated state of matter, called plasma, which can form unstable structures that reduce the efficiency of those reactions.

• Electrically controllable 3D magnetic hopfions realized in chiral magnets

  A research team from the High Magnetic Field Laboratory of the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, together with collaborators from Anhui University, ShanghaiTech University, and the University of New Hampshire, has demonstrated the first electrically controllable generation of hopfions—three-dimensional topological solitons—in a solid-state magnetic system. The results are published online in Nature Materials.

• AI captures particle accelerator behavior to optimize machine performance

  Keeping high-power particle accelerators at peak performance requires advanced and precise control systems. For example, the primary research machine at the U.S. Department of Energy's Thomas Jefferson National Accelerator Facility features hundreds of fine-tuned components that accelerate electrons to 99.999% the speed of light.

• The shape of skis makes the biggest difference in maneuverability

  From the biathlon to the slopestyle to the giant slalom, raising a ski above your head after crossing the finish line is the triumphant Olympic skier's standard celebration. But why do the skis of the competitors in each event look so different?

• Cutting down on quantum-dot crosstalk: Precise measurements expose a new challenge

  Devices that can confine individual electrons are potential building blocks for quantum information systems. But the electrons must be protected from external disturbances. RIKEN researchers have now shown how quantum information encoded into a so-called quantum dot can be negatively affected by nearby quantum dots. This has implications for developing quantum information devices based on quantum dots.

• Physicists develop new protocol for building photonic graph states

  Physicists have long recognized the value of photonic graph states in quantum information processing. However, the difficulty of making these graph states has left this value largely untapped. In a step forward for the field, researchers from The Grainger College of Engineering at the University of Illinois Urbana-Champaign have proposed a new scheme they term "emit-then-add" for producing highly entangled states of many photons that can work with current hardware. Published in npj Quantum Information, their strategy lays the groundwork for a wide range of quantum enhanced operations including measurement-based quantum computing.