Phys.org October 5, 2023 The coupling of microwave and optical systems presents a challenge due to the natural incompatibility of energies, but potential applications range from optical interconnects for quantum computers to next-generation quantum microwave sensors, detectors, and coherent imagers. Emerging platforms are constrained by specific conditions. An international team of researchers (Poland, Denmark) designed a set-up using Rydberg atoms that allows wideband coupling of optical and microwave photons at room temperature. They demonstrated continuous-wave conversion of a 13.9 GHz field to a near-infrared optical signal using an ensemble of Rydberg atoms via a free-space six-wave mixing process designed to minimize […]
Generating circularly polarised light
Nanowerk October 5, 2023 Hybrid perovskite semiconductor materials are predicted to lock chirality into place and encode asymmetry into their electronic states, while softness of their crystal lattice accommodates lattice strain to maintain high crystal quality with low defect densities. An international team of researchers (Germany, France, USA – Harvard University) has reported photoluminescence quantum efficiencies as high as 39% and degrees of circularly polarized photoluminescence of up to 52%, at room temperature, in the chiral layered hybrid lead-halide perovskites. Using transient chiroptical spectroscopy, they explained the photoluminescence yields from suppression of nonradiative loss channels and high rates of radiative […]
Illuminating errors creates a new paradigm for quantum computing
Phys.org October 11, 2023 For eventual application in quantum error correction, it is advantageous to realize qubits with structured error models, such as biased Pauli errors or conversion of errors into detectable erasures. An international team of researchers (USA – Princeton University, Yale University, France) demonstrated a new neutral atom qubit using the nuclear spin of a long-lived metastable state in 171Yb. The long coherence time and fast excitation to the Rydberg state allowed one- and two-qubit gates with fidelities of 0.9990(1) and 0.980(1), respectively. A large fraction of all gate errors results in decays out of the qubit subspace […]
Nanoscale rust: The future of magnets?
Phys.org October 5, 2023 Multiferroics have tremendous potential to revolutionize logic and memory devices through new functionalities and energy efficiencies. To better understand and enhance their ferroic orders and couplings an international team of researchers (Canada, USA – Lawrence Berkeley National Laboratory, Argonne National Laboratory) used epsilon iron oxide (ϵ-Fe2O3) as a model system with a simplifying single magnetic ion. Using 15, 20, and 30 nm nanoparticles, they found that a modified and size-dependent Fe–O hybridization changed the spin–orbit coupling. However, the size effects disappeared in the high-temperature phase where the strongest Fe–O hybridization occurred. By manipulating hybridization, they could […]
NASA Scientists Got a Surprise When They Opened Up Sample of Bennu Asteroid Dust
Science Alert October 5, 2023 The robotic arm, Touch-and-Go Sample Acquisition Mechanism (TAGSAM) reached out and grabbed a bunch of dirt from asteroid Bennu, which was finally delivered to Earth in late September after an epic 7-year mission. That initial analysis includes scanning electron microscopy, infrared measurements, and X-ray diffraction. NASA will be hosting a press conference at 11:00 ET on October 11 to reveal the results, as well as the first images of the sample. An estimated 250 grams of Bennu dust is inside the TAGSAM head. Over the coming weeks, the container will be moved to a new, […]
New easy-to-use optical chip can self-configure to perform various functions
Phys.org October 11, 2023 To enhance the functional versatility of chips researchers in China introduced the concept of reconfiguration into photonic integrated circuits. Inspired by field programmable gate arrays in the electrical domain, they developed programmable photonic chips employing various topologies. However, users still encounter challenges when utilizing these devices, as they need to understand the internal structure and principles of the chip and individually adjust the tunable basic units within the topology network. The researchers employed the quadrilateral topological network based on the on-chip Mach–Zehnder interferometer as a black box to realize a highly self-reconfigurable optical signal processor. By […]
Physics Revelation Could Mean We’re All Living in a Simulation
Phys.org October 10, 2023 The simulation hypothesis is a philosophical theory, in which the entire universe and our objective reality are just simulated constructs. Despite the lack of evidence, this idea is gaining traction in scientific circles as well as in the entertainment industry. Recent scientific developments in the field of information physics, such as the publication of the mass-energy-information equivalence principle, appear to support this possibility. In particular, the 2022 discovery of the second law of information dynamics (infodynamics) facilitates new and interesting research tools at the intersection between physics and information. Researchers in the UK re-examined the second […]
Research shows how topology can help create magnetism at higher temperatures
Phys.org October 10, 2023 The interplay between magnetism and electronic band topology enriches topological phases and has promising applications. However, the role of topology in magnetic fluctuations has been elusive. A team of researchers in the US (MIT, Harvard University, Argonne National Laboratory, SLAC National Accelerator Laboratory, Oak Ridge National Laboratory, Brookhaven National Laboratory, industry, Rice University) has shown evidence for topology stabilized magnetism above the magnetic transition temperature in magnetic Weyl semimetal candidate CeAlGe. They had clear indication of the presence of locally correlated magnetism within a narrow temperature window well above the thermodynamic magnetic transition temperature. Effective field […]
Researchers use new cobalt-modified nano material to make fuel cells more robust, sustainable
Phys.org October 11, 2023 Using the Pt metal as the shell material of the catalyst in polymer electrolyte membrane fuel cells not only increases the surface area but also creates an interfacial interaction between the core metal and platinum, which results in enhanced catalytic activity. Researchers in Canada surface doped Pd@Pt nanoparticles with cobalt to further boost their durability and activity. Characterizing the synthesized catalyst with X-ray absorption fine structure at the Pt L3-edge and cobalt K-edges, together with performance tests, revealed information about the effect of the dopants on the catalytic activity of catalysts. The results of the local […]