Phys.org August 6, 2020 Electrical control of magnetism in van der Waals ferromagnetic semiconductors is an important step in creating novel spintronic devices capable of processing and storing information. Using an electric double-layer transistor device, an international team of researchers (Singapore, UK, China) discovered that the magnetism of a magnetic semiconductor, Cr2Ge2Te6, shows exceptionally strong response to applied electric fields. With electric fields applied, the material was found to exhibit ferromagnetism at temperatures up to 200 K (-73°C). At such temperatures, ferromagnetic order is normally absent in this material. Their analysis suggests that heavy doping promotes a double-exchange mechanism that […]
Greater connectedness in remote areas: A Ka-band transceiver for satellite communications
EurekAlert August 4, 2020 The transceiver developed by researchers in Japan using standard CMOS technology uses 27-31 GHz frequency range for uplink and 17-21 GHz range for downlink. A high-quality transformer is used to achieve efficient power use and high linearity in transmission, resulting in lower distortion during transmission. Two RX channels allows for receiving signals from two satellites simultaneously in parallel using either two independent polarization modes or two different frequencies. It can perform adjacent-channel interference cancellation increasing the dynamic range of the system, thus allowing it to operate correctly even in less-than-ideal scenarios with stronger noise and interference. […]
Has the Summit Supercomputer Cracked COVID’s Code?
IEEE Spectrum August 2, 2020 According to a team of researchers in the US (Oak Ridge National Laboratory, University Tennessee, University of Cincinnati, University of Kentucky, Yale University, medical schools) lung fluid samples from COVID-19 patients consistently revealed over-expression of genes that produce bradykinin, while also under-expressing genes that would inhibit or break down bradykinin. This is the core mechanism that explains a lot of the symptoms. They arrived at this conclusion by crunching data sets representing some 17,000 genetic samples while comparing each of these samples to some 40,000 genes. They highlight ten possible therapies developed for other conditions […]
Image cloaking tool thwarts facial recognition programs
TechXplore August 5, 2020 To help individuals inoculate their images against unauthorized facial recognition models, researchers at the University of Chicago have developed a system called Fawkes. It helps individuals add imperceptible pixel-level changes (they call “cloaks”) to their own photos before releasing them. When used to train facial recognition models, the “cloaked” images produce functional models that consistently cause normal images of the user to be misidentified. In experiments Fawkes provided 95+% protection against user recognition regardless of how trackers train their models. They have shown that Fawkes is robust against a variety of countermeasures that try to detect […]
Novel approach improves graphene-based supercapacitors
EurekAlert August 3, 2020 Researchers in Australia have developed a technique to improve the performance of quasi‐solid‐state supercapacitors made by graphitized silicon carbide on silicon electrodes and polyvinyl alcohol (PVA)+H2SO4 gel electrolyte. They increased the specific capacitance of the cell up to 3‐fold resulting from a simple agent‐free, in situ, electrochemical treatment leading to functionalization of the graphitic electrodes. The functionalization of the electrodes simultaneously enables redox reactions, without adding any redox agent, and increases the overall capacitance…read more. TECHNICAL ARTICLE
Novel magnetic stirrer speaks to lab equipment
Science Daily August 3, 2020 Researchers in the UK have developed a device, called “Smart Stirrer”. When immersed in a solution, it can in situ monitor physical properties of the chemical reaction such as the temperature, conductivity, visible spectrum, opaqueness, stirring rate, and viscosity. This data is transmitted real-time over a wireless connection to an external system, such as a PC or smartphone. The flexible open-source software architecture allows effortless programming of the operation parameters of the Smart Stirrer in accordance with the end-user needs. In a series of experiments its capability for many hours of continuous telemetry with fine […]
NTU Singapore scientists build ultra-high-speed Terahertz wireless chip
EurekAlert August 5, 2020 Conventional approaches to terahertz waveguiding suffer from sensitivity to defects and sharp bends. Building on the topological phase of light, an international team of researchers (Singapore, Japan) experimentally demonstrated robust terahertz topological valley transport through several sharp bends on the all-silicon chip. The valley kink states are excellent information carriers owing to their robustness, single-mode propagation, and linear dispersion. They have demonstrated error-free communication through a highly twisted domain wall at an unprecedented data transfer rate (exceeding ten gigabits per second) that enables real-time transmission of uncompressed 4K high-definition video. The research opens a route towards […]
Physicists find misaligned carbon sheets yield unparalleled properties
Science Daily July 31, 2020 In an earlier study an international team of researchers (Yale University, UT Dallas, Japan) showed that when offset by 0.93 degrees, twisted bilayer graphene exhibits both superconducting and insulating states, thereby widening the magic angle significantly. In the current research they set out to determine how mid-infrared light might affect the conductance of electrons in twisted bilayer graphene. Their work involved calculating the light absorption based on the moiré pattern’s band structure. They showed that the theoretical results not only matched well with the experimental findings, but also pointed to a mechanism that is fundamentally […]
Scientists discover new class of semiconducting entropy-stabilized materials
Science Daily July 31, 2020 Almost all entropy-stabilized materials so far are either conducting metals or insulating ceramics. Researchers at the University of Michigan have experimentally synthesized and characterized a new class of the multicationic and -anionic entropy-stabilized chalcogenide alloys based on the (Ge,Sn,Pb)(S,Se,Te) formula. The configurational entropy from the disorder of both the anion and the cation sublattices reaches a record value for the equimolar composition and stabilizes the single-phase solid solution. Theoretical calculations and experiments both show that the synthesized alloys are thermodynamically stable at the growth temperature and kinetically metastable at room temperature. Doping and electronic transport […]
Scientists find way to track space junk in daylight
Phys.org August 4, 2020 Utilizing a higher-powered laser, space debris laser ranging detects diffuse reflections from defunct satellites or rocket bodies up to 3000 km. So far space debris laser ranging was only possible within a few hours around twilight while it is dark at the satellite laser ranging station and space debris is illuminated by the sun. An international team of researchers (Austria, Spain, Germany) has extended the visible window using a combination of a telescopic detector and filter to increase the contrast of objects as they appear against the sky during the day. Overall, the new technique could […]