Phys.org Physics News Feeds

  • Researchers develop algorithm to see inside materials with subatomic particles
    on May 17, 2021 at 3:56 pm

    The University of Kent’s School of Physical Sciences, in collaboration with the Science and Technology Facilities Council (STFC) and the Universities of Cardiff, Durham and Leeds, have developed an algorithm to train computers to analyze signals from subatomic particles embedded in advanced electronic materials.

  • Quantum computing: Cold chips can control qubits
    on May 17, 2021 at 1:46 pm

    Researchers and engineers from QuTech in the Netherlands and from Intel Corp., jointly designed and tested a chip to control qubits that can operate at extremely low temperatures, and opens the door to solving the “wiring bottleneck,” an important step toward a scalable quantum computer. Their results are published in the scientific journal Nature.

  • Using micro-sized cut metal wires, team forges path to new uses for terahertz waves
    on May 14, 2021 at 4:05 pm

    Japanese researchers successfully tested reflectionless, highly refractive index metasurface that may eventually be used in practical applications to send, receive, and manipulate light and radio waves in the terahertz waveband (THz). THz is measured in millionths of a meter, known as micrometers. The metasurface, an artificial two-dimensional flat material, was made of micro-sized cut metal wires of silver paste ink placed on both the front and back of a polyimide film. The team, led by Takehito Suzuki, Associate Professor at the Tokyo University of Agriculture and Technology (TUAT) Institute of Engineering, published their findings on April 29, 2021 in Optics Express.

  • Nanophotonics enhanced coverslip for phase imaging in biology
    on May 14, 2021 at 4:04 pm

    The ability to visualize transparent objects such as biological cells is of fundamental importance in biology and medical diagnostics. Conventional approaches to achieve this include phase-contrast microscopy and techniques that rely on chemical staining of biological cells. These techniques, however, rely on expensive and bulky optical components or require changing, and in some cases damaging, the cell by introducing chemical contrast agents. Significant recent advances in nanofabrication technology permit structuring materials on the nanoscale with unprecedented precision. This has given rise to the revolutionary field of meta-optics that aims to develop ultra-compact optical components that replace their bulk-optical counterparts as for example lenses and optical filters. Such meta-optical devices exhibit unusual properties for which they have recently drawn significant scientific interest as novel platforms for imaging applications.

  • Is the past (and future) there when nobody looks?
    on May 14, 2021 at 2:52 pm

    In 1961, the Nobel prize winning theoretical physicist Eugene Wigner proposed what is now known as the ‘Wigner’s friend’ thought experiment as an extension of the notorious Schroedinger’s cat experiment. In the latter, a cat is trapped in a box with poison that will be released if a radioactive atom decays. Governed by quantum mechanical laws, the radioactive atom is in a superposition between decaying and not decaying, which also means that the cat is in a superposition between life and death. What does the cat experience when it is in the superposition? Wigner sharpened the question by pushing quantum theory to its conceptual limits. He investigated what happens when an observer also has quantum properties.

  • To make particles flow more efficiently, put an obstacle in their way
    on May 14, 2021 at 1:47 pm

    Scientists used to perform experiments by stirring biological and chemical agents into test tubes.

  • Detector technology yields unprecedented 3D images, heralding far larger application to study neutrinos
    on May 14, 2021 at 1:39 pm

    An experiment to capture unprecedented 3D images of the trajectories of charged particles has been demonstrated using cosmic rays as they strike and travel through a cryostat filled with a ton of liquid argon. The results confirm the capabilities of a novel detector technology for particle physics developed by researchers at Lawrence Berkeley National Laboratory (Berkeley Lab) in collaboration with several university and industrial partners.

  • Fully integrated ‘hot qubit’ quantum processor using commercially available technology
    on May 14, 2021 at 1:38 pm

    Equal1 Laboratories (Equal1), a silicon-based quantum computing company, today announced the company is the first to demonstrate a fully integrated quantum processor unit (QPU) operating at 3.7 kelvin ― a major milestone with implications for the trajectory of quantum computing.

  • Modular blue light-sensitive photoswitch developed for optogenetic engineering
    on May 14, 2021 at 12:11 pm

    Recently, Prof. WANG Junfeng from the High Magnetic Field Laboratory of the Hefei Institutes of Physical Science (HFIPS), together with international scholars, developed a novel circular permutated light-oxygen-voltage 2 (LOV2) to expand the repertoire of genetically encoded photoswitches, which will accelerate the design of novel optogenetic devices. The result was published in Nature Chemical Biology.

  • Current trend reversed: Scientists investigate the Seebeck effect in electric current
    on May 13, 2021 at 4:49 pm

    When a piece of conducting material is heated up at one of its ends, a voltage difference can build up across the sample, which in turn can be converted into a current. This is the so-called Seebeck effect, the cornerstone of thermoelectric effects. In particular, the effect provides a route to creating work out of a temperature difference. Such thermoelectric engines do not have any movable part and are therefore convenient power sources in various applications, including propelling NASA’s Mars rover Perseverance. The Seebeck effect is interesting for fundamental physics, too, as the magnitude and sign of the induced thermoelectric current is characteristic of the material and indicates how entropy and charge currents are coupled. Writing in Physical Review X, the group of Prof. Tilman Esslinger at the Department of Physics of ETH Zurich now reports on the controlled reversal of such a current by changing the interaction strength among the constituents of a quantum simulator made of extremely cold atoms trapped in shaped laser fields. The capability to induce such a reversal means that the system can be turned from a thermoelectric engine into a cooler.

  • Researchers 3D print complex micro-optics with improved imaging performance
    on May 13, 2021 at 4:49 pm

    In a new study, researchers have shown that 3D printing can be used to make highly precise and complex miniature lenses with sizes of just a few microns. The microlenses can be used to correct color distortion during imaging, enabling small and lightweight cameras that can be designed for a variety of applications.

  • Long-lost letter from Einstein discusses link between physics and biology—70 years before evidence emerges
    on May 13, 2021 at 4:00 pm

    Since the dawn of the electronic age, it has never been easier for researchers to engage with the general public—gaining access to precious resources otherwise unavailable.

  • New evidence for electron’s dual nature found in a quantum spin liquid
    on May 13, 2021 at 3:40 pm

    A new discovery led by Princeton University could upend our understanding of how electrons behave under extreme conditions in quantum materials. The finding provides experimental evidence that this familiar building block of matter behaves as if it is made of two particles: one particle that gives the electron its negative charge and another that supplies its magnet-like property, known as spin.

  • Freeform imaging systems: Fermat’s principle unlocks ‘first time right’ design
    on May 13, 2021 at 3:40 pm

    Researchers at Brussels Photonics, Vrije Universiteit Brussel, have developed a ‘first time right’ design method that eliminates the “step-and-repeat” and “trial-and-error” approach in optical system design. They demonstrated the systematic, deterministic, scalable, and holistic character of their disruptive technique with various freeform lens- and mirror-based high-end examples and invite optical designers to experience their new method hands-on via an open-access trial web application.

  • Non-linear optics meets X-rays
    on May 13, 2021 at 3:31 pm

    The recent advent of femtosecond X-ray sources offers unprecedented opportunities for structural and dynamical studies. It requires, however, manipulating spectral properties, as commonly done by non-linear optics at visible/infrared wavelengths. Here we show the first evidence for Self-Phase Modulation, a key non-linear effect in ultrafast laser science, in soft X-Rays. Building on such an effect, we demonstrate how to tune spectral properties in this wavelength region critical for core electron pump-probe spectroscopy and nanoimaging.

  • Why precision luminosity measurements matter
    on May 13, 2021 at 3:31 pm

    The ATLAS and CMS experiments at the Large Hadron Collider (LHC) have performed luminosity measurements with spectacular precision. A recent physics briefing from CMS complements earlier ATLAS results and shows that by combining multiple methods, both experiments have reached a precision better than 2%. For physics analyses—such as searches for new particles, rare processes or measurements of the properties of known particles—it is not only important for accelerators to increase luminosity, but also for physicists to understand it with the best possible precision.

  • CDEX listens to the sound of cosmology from a laboratory deep underground
    on May 13, 2021 at 3:28 pm

    Much compelling evidence from astroparticle physics and cosmology indicate that the major matter component in the Universe is dark matter, accounting for about 85% with the remaining 15% ordinary matter. Nevertheless, people still know little about dark matter, including its mass and other properties. Many models predict dark matter particles could couple with ordinary particles at the weak interaction level, so it is possible to capture the signal of dark matter particles with direct detection experiment.

  • Quantum machine learning hits a limit
    on May 13, 2021 at 12:58 pm

    A new theorem from the field of quantum machine learning has poked a major hole in the accepted understanding about information scrambling.

  • Previously unknown letter reveals Einstein’s thinking on bees, birds and physics
    on May 13, 2021 at 7:06 am

    The 1949 letter by the physicist and Nobel laureate discusses bees, birds and whether new physics principles could come from studying animal senses.

  • Better integrated circuits with glide symmetry
    on May 12, 2021 at 6:11 pm

    Surface plasmon polaritons (SPPs) are highly localized surface waves on the interface between metal and dielectric in the optical frequency band. SPPs do not naturally exist in the microwave and terahertz frequencies, so “spoof” surface plasmon polaritons (SSPPs) are necessary for operations in those lower frequency bands.

  • Excitation spectral microscopy integrates multi-target imaging and quantitative biosensing
    on May 12, 2021 at 5:05 pm

    The multiplexing capability of fluorescence microscopy is severely limited by the broad fluorescence spectral width. Spectral imaging offers potential solutions, yet typical approaches to disperse the local emission spectra notably impede the attainable throughput and place substantial constraints on temporal resolution. Tunable bandpass filters provide a possibility to scan through the emission wavelength in the wide field. However, applying narrow bandpasses to the fluorescence emission results in inefficient use of the scarce signal.

  • X-ray ptychography performed for first time at small-scale laboratory
    on May 12, 2021 at 2:59 pm

    In recent years, X-ray ptychography has revolutionized nanoscale phase contrast imaging at large-scale synchrotron sources. The technique produces quantitative phase images with the highest possible spatial resolutions (10’s nm) – going well beyond the conventional limitations of the available X-ray optics—and has wide reaching applications across the physical and life sciences. A paper published in Physical Review Letters on 12 May 2021, reveals that an international collaboration of scientists has demonstrated for the first time how the technique of high-resolution phase contrast diffraction imaging can be performed with small-scale laboratory sources.

  • Physicists extract proton mass radius from experimental data
    on May 12, 2021 at 2:57 pm

    Researchers have recently extracted the proton mass radius from experimental data. A research group at the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS) presented an analysis of the proton mass radius in Physical Review D on May 11. The proton mass radius is determined to be 0.67 ± 0.03 femtometers, which is obviously smaller than the charge radius of the proton.

  • Brand new physics of superconducting metals refuted by Lancaster physicists
    on May 12, 2021 at 9:00 am

    Lancaster scientists have demonstrated that other physicists’ recent “discovery” of the field effect in superconductors is nothing but hot electrons after all.

  • Harnessing the hum of fluorescent lights for more efficient computing
    on May 12, 2021 at 9:00 am

    The property that makes fluorescent lights buzz could power a new generation of more efficient computing devices that store data with magnetic fields, rather than electricity.

  • How to thermally cloak an object
    on May 12, 2021 at 7:13 am

    Can you feel the heat? To a thermal camera, which measures infrared radiation, the heat that we can feel is visible, like the heat of a traveler in an airport with a fever or the cold of a leaky window or door in the winter.

  • World’s fastest information-fueled engine designed by university researchers
    on May 11, 2021 at 8:22 pm

    Simon Fraser University researchers have designed a remarkably fast engine that taps into a new kind of fuel—information.

  • Researchers use optical data to reveal the basic structure of spacetime in rotating frames
    on May 11, 2021 at 3:41 pm

    One of the most basic structural aspects of relativistic spacetime is the description of how time and distances are altered by motion. The theory of special relativity describes a spacetime framework for linear constant motion in which time dilates and lengths contract in response to motion. This framework is described by the Lorentz transformation, which encompasses mathematical formulas that describe how time and distance are altered between moving reference frames. The Lorentz transformation also describes how a stationary observer views time in the moving frame to be offset with distance. The offsetting of time with distance between reference frames generates differential simultaneity, in which events that are simultaneous for one observer will not be simultaneous for a second observer moving relative to the first observer.

  • Researchers develop magnetic thin film for spin-thermoelectric energy conversion
    on May 11, 2021 at 3:38 pm

    A team of researchers, affiliated with UNIST has recently introduced a new class of magnetic materials for spin caloritronics. Published in the February 2021 issue of Nature Communications, the demonstrated STE applications of a new class of magnets will pave the way for versatile recycling of ubiquitous waste heat. This breakthrough has been led by Professor Jung-Woo Yoo and his research team in the Department of Materials Science and Engineering at UNIST.

  • Researchers generate tunable twin particles of light
    on May 11, 2021 at 3:34 pm

    Identical twins might seem ‘indistinguishable,’ but in the quantum world the word takes on a new level of meaning. While identical twins share many traits, the universe treats two indistinguishable quantum particles as intrinsically interchangeable. This opens the door for indistinguishable particles to interact in unique ways—such as in quantum interference—that are needed for quantum computers.