Phys.org Physics

• OLEDs can now switch light's handedness with an electrical signal

  Researchers from the University of Oxford have for the first time discovered an approach to electrically switch organic LEDs (OLEDs) to emit either left- or right-handed circularly polarized light without changing the light-emitting molecules. This could be useful for a range of technological applications, from more energy efficient OLED displays, to optical information transfer.

• New X-ray method captures 3 image-contrast types in a single shot

  University of Houston researchers developed a new X-ray imaging method capable of revealing hidden features in a single shot, a breakthrough that could advance cancer detection, disease monitoring, security screening and material analysis.

• Adaptive method helps light-based quantum processors act more like neural networks

  Machine learning models called convolutional neural networks (CNNs) power technologies like image recognition and language translation. A quantum counterpart—known as a quantum convolutional neural network (QCNN)—could process information more efficiently by using quantum states instead of classical bits.

• Experimental proof shows quantum world is even stranger than previously thought

  The quantum world is famously weird—a single particle can be in two places at once, its properties are undefined until they are measured, and the very act of measuring a quantum system changes everything. But according to new research published in Physical Review Letters, the quantum world is even stranger than previously thought.

• Quantum key distribution enables secure communication via hybrid and mobile channels

  As part of the QuNET project, researchers have demonstrated how quantum key distribution works reliably via hybrid and mobile channels. The results are milestones for sovereign, quantum-secured communication in Germany and have been published in the New Journal of Physics.

• Anomalous electronic state opens pathway to room-temperature superconductivity

  Superconductive materials can conduct electricity with no resistance, but typically only at very low temperatures. Realizing superconductivity at room temperature could enable advanced, energy-efficient electronics and other technologies.

• Defining work and heat in quantum systems: Laser light coherence offers a consistent approach

  Researchers at the University of Basel have developed a new approach to applying thermodynamics to microscopic quantum systems.

• Consciousness as the foundation: New theory addresses nature of reality

  Consciousness is fundamental; only thereafter do time, space and matter arise. This is the starting point for a new theoretical model of the nature of reality, presented by Maria Strømme, Professor of Materials Science at Uppsala University, in AIP Advances. The article has been selected as the best paper of the issue and featured on the cover.

• Particle accelerator waste could help produce cancer-fighting materials

  Energy that would normally go to waste inside powerful particle accelerators could be used to create valuable medical isotopes, scientists have found.

• New p-wave magnet with helix spin structure could enable smaller computer chips

  A novel magnetic material with an extraordinary electronic structure might allow for the production of smaller and more efficient computer chips in the future: the p-wave magnet. Researchers from Karlsruhe Institute of Technology (KIT) were involved in its development.

• Quantum photonic chip integrates light-emitting molecules with single-mode waveguides

  Photonic quantum processors, devices that can process information leveraging quantum mechanical effects and particles of light (photons), have shown promise for numerous applications, ranging from computations and communications to the simulation of complex quantum systems.

• New substitution method enables high-precision nuclear reaction measurements using natural copper

  A joint research team has made important progress in the field of photoneutron cross section measurement. The team proposed a substitution measurement method that avoids the use of expensive and hard-to-prepare high-purity isotope targets, successfully measuring the 65Cu(γ,n)64Cu reaction cross section with high precision. This method only relies on natural copper (natCu) and previously measured copper-63 (63Cu) data, without modifying experimental facility parameters, making it simple, efficient, and low-cost.

• Quantum ground states: Scalable counterdiabatic driving technique enables reliable and rapid preparation

  Quantum ground states are the states at which quantum systems have the minimum possible energy. Quantum computers are increasingly being used to analyze the ground states of interesting systems, which could in turn inform the design of new materials, chemical compounds, pharmaceutical drugs and other valuable goods.

• Metasurfaces etched into 2D crystals boost nonlinear optical effects at nanoscale

  In January, a team led by Jim Schuck, professor of mechanical engineering at Columbia Engineering, developed a method for creating entangled photon pairs, a critical component of emerging quantum technologies, using a crystalline device just 3.4 micrometers thick.

• Laser-induced break-up of C₆₀ fullerenes caught in real-time on X-ray camera

  The understanding of complex many-body dynamics in laser-driven polyatomic molecules is crucial for any attempt to steer chemical reactions by means of intense light fields. Ultrashort and intense X-ray pulses from accelerator-based free electron lasers (FELs) now open the door to directly watch the strong reshaping of molecules by laser fields.

• Atoms passing through walls: Quantum tunneling of hydrogen within palladium crystal

  At low temperatures, hydrogen atoms move less like particles and more like waves. This characteristic enables quantum tunneling, the passage of an atom through a barrier with a higher potential energy than the energy of the atom. Understanding how hydrogen atoms move through potential barriers has important industrial applications. However, the small size of hydrogen atoms makes direct observation of their motion extremely challenging.

• Symmetry simplifies quantum noise analysis, paving way for better error correction

  Researchers from the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, and Johns Hopkins University in Baltimore have achieved a breakthrough in quantum noise characterization in quantum systems—a key step toward reliably managing errors in quantum computing.

• Physicists explore optical launch of hypersound pulses in halide perovskites

  A German-French team of physicists from TU Dortmund University, University of Würzburg, and Le Mans Université has succeeded in launching shear hypersound pulses with exceptionally large amplitudes in metal halide perovskites using pulsed optical excitation.

• What would a small black hole do to the human body? Scientist aims to answer that

  Some people may worry about being bitten by a snake or spider, but have you ever considered what would happen if a small black hole tried to pass through your body?

• Single-photon switch could enable photonic computing

  There are few technologies more fundamental to modern life than the ability to control light with precision. From fiber-optic communications to quantum sensors, the manipulation of photons underpins much of our digital infrastructure. Yet one capability has remained frustratingly out of reach: controlling light with light itself at the most fundamental level using single photons to switch or modulate powerful optical beams.

• Final experimental result for the muon still challenges theorists

  For experimental physicists, the latest measurement of the muon is the best of times. For theorists there's still work to do.

• Mirror symmetry prompts ultralow magnetic damping in 2D van der Waals ferromagnets

  Two-dimensional (2D) van der Waals (vdW) ferromagnets are thin and magnetic materials in which molecules or layers are held together by weak attractive forces known as vdW forces. These materials have proved to be promising for the development of spintronic devices, systems that operate leveraging the spin (i.e., intrinsic angular momentum) of electrons, as opposed to electric charge.

• Quantum calculations expose hidden chemistry of ice

  When ultraviolet light hits ice—whether in Earth's polar regions or on distant planets—it triggers a cascade of chemical reactions that have puzzled scientists for decades.

• Watching gold's atomic structure change at 10 million times Earth's atmospheric pressure

  The inside of giant planets can reach pressures more than one million times the Earth's atmosphere. As a result of that intense pressure, materials can adopt unexpected structures and properties. Understanding matter in this regime requires experiments that push the limits of physics in the laboratory.

• From light to logic: First complete logic gate achieved in soft material using light alone

  Researchers from McMaster University and the University of Pittsburgh have created the first functionally complete logic gate—a NAND gate (short for "NOT AND")—in a soft material using only beams of visible light. The discovery, published in Nature Communications, marks a significant advance in the field of materials that compute, in which materials themselves process information without traditional electronic circuitry.