Phys.org Physics

• Challenging a 300-year-old law of friction

  Researchers at the University of Konstanz have uncovered a new mechanism of sliding friction: resistance to motion that arises without any mechanical contact, driven purely by collective magnetic dynamics. The study, published in Nature Materials, shows that friction does not necessarily increase steadily with load, as postulated by Amontons' law—one of the oldest and most fundamental empirical laws of physics—but can instead exhibit a pronounced maximum when internal magnetic ordering becomes frustrated.

• Microwave quantum network shows resilience against heat-related disturbances

  Quantum communication systems are emerging solutions to transmit information between devices in a network leveraging quantum mechanical phenomena, such as entanglement. Entanglement is a quantum effect that entails a link between two or more particles that share a unified state even at a distance, so that measuring one instantly affects the other.

• Dark matter experiment reaches ultracold milestone

  An international collaboration, including Northwestern University, has reached a critical milestone in the search for dark matter, the mysterious substance that makes up about 85% of all matter in the universe. Located two kilometers below ground in Canada, the Super Cryogenic Dark Matter Search (SuperCDMS) at SNOLAB has cooled to its operating temperature, the collaboration announced on March 17.

• Proof-of-concept quantum battery shows faster charging as it gets larger

  Australian scientists have made a significant leap forward in energy storage technology with the world's first proof-of-concept quantum battery. Similar to conventional batteries, this quantum version charges, stores and discharges energy—and is the first to do so.

• Quantum-inspired laser system delivers distance measurements with sub-millimeter accuracy

  A new laser range-finding technique, inspired by quantum physics, that can measure distances under strong solar background has been demonstrated by researchers at the University of Bristol. The team has proved their hypothesis by testing out their new method on some of the university's most iconic buildings.

• Experiment observes quantum radiation reaction as electrons hit an ultra-intense laser

  For the first time, a quantum radiation reaction in strong electromagnetic fields has been demonstrated experimentally by allowing electrons to collide with an extremely intense and powerful laser beam. The research findings provide insights needed for new quantum-mechanical computational models and clues to how the laws of physics operate near neutron stars or black holes.

• Mathematical foundations for noise-tolerant quantum catalysts in real-world environments

  Quantum catalysts are specialized resources that enable quantum state transformations previously thought impossible, holding promise for advancements in quantum computing and thermodynamics. A recent international study has identified the conditions under which these catalysts can operate reliably even amid environmental noise, marking a significant step toward practical quantum technologies.

• Scientists discover new heavy proton-like particle at CERN

  Scientists from the University of Manchester have played a leading role in the discovery of a new subatomic particle at CERN's Large Hadron Collider (LHC). The particle, known as the Ξcc⁺ (Xi‑cc‑plus), is a new type of heavy proton-like particle containing two charm quarks and one down quark.

• Perovskite crystals can host qubits, challenging long-held assumptions

  For the first time, researchers have demonstrated that the properties of the perovskite family of materials can be used to create so-called quantum bits. The findings, published in the journal Nature Communications, pave the way for more affordable materials in future quantum computers.

• Ultrafast laser pulses bring diamond-based quantum internet closer to reality

  The controlled generation of single photons is an essential element of numerous quantum technology applications, such as quantum networks and quantum computing. A research team has now demonstrated the successful application of the new SUPER (Swing-UP of the quantum EmitteR population) method. The approach facilitates the controlled generation of light particles (photons). Results of the study were recently published in the journal Nature Communications.

• Superconductor advancement could unlock ultra-energy-efficient electronics

  Superconducting materials could play a crucial role in the energy-efficient applications of the future. However, several technical challenges still stand in the way of their practical use. Now, researchers at Chalmers University of Technology in Sweden have developed a new material design that addresses a major obstacle in the field: enabling superconductivity to operate at higher temperatures while also withstanding strong magnetic fields. This breakthrough could pave the way for far more energy-efficient electronics and quantum technologies.

• Discrete time crystal acts as a usable sensor for weak magnetic oscillations

  The bizarre properties of discrete time crystals could be harnessed to detect extremely subtle oscillations of magnetic fields, physicists in the US and Germany have revealed. Publishing their results in Nature Physics, a team led by Ashok Ajoy at the University of California, Berkeley, show for the first time that these exotic materials could have practical uses far beyond their current status as an impractical curiosity.

• A clear roadmap for engineering combs of light

  Optical frequency combs—laser sources that emit evenly spaced colors of light—are foundational, ubiquitous tools for precision measurement, found in optical clocks, gas-sensing spectrometers, and instruments that detect the light signatures of exoplanets. Traditionally, frequency combs are produced by large, fiber-laser systems ranging from the size of a shoebox to a refrigerator.

• Laser-assisted electron scattering seen with circularly polarized light for the first time

  Researchers from Tokyo Metropolitan University have succeeded in detecting laser-assisted electron scattering (LAES) using circularly polarized light for the first time. The use of circularly polarized light promises valuable insights into how atomic scale "helicity" impacts how electrons interact with matter and light.

• Not just spin—electron orbitals can provide new method for controlling magnetism

  Research is actively underway to develop a "dream memory" that can reduce heat generation in smartphones and laptops while delivering faster performance and lower power consumption. Korean researchers propose a new possibility for controlling magnetism using the exchange interaction of electron orbitals—the motion of electrons orbiting around an atomic nucleus—rather than relying on the conventional exchange interaction of electron spin, the rotational property of electrons inside semiconductors.

• 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.