Phys.org October 18, 2021 Magnetic solids can be demagnetized quickly with a short laser pulse. However, the microscopic mechanisms of ultrafast demagnetization remain unclear. Researchers in Germany have developed a method to quantify the temperature-dependent electron–phonon scattering rate in gadolinium measuring independently the electron-phonon scattering rate for the 5d and the 4f electrons. They deduced the temperature dependence of scattering for the 5d electrons, while no effect on the phonon population is observed for the 4f electrons. The results suggest that the ultrafast magnetization dynamics in Gd is triggered by the spin-flip in the 5d electrons, found evidence of the […]
Ultrafast optical switching can save overwhelmed datacenters
Phys.org October 15, 2021 Optical circuit switches can offer high bandwidth, low network latency and an energy-efficient and scalable data center network. However, it is critical to switch between wavelengths at nanosecond (ns) timescales. An international team of researchers (Switzerland, UK) has demonstrated ultrafast optical circuit switches based on a microcomb and semiconductor optical amplifiers (SOAs). They used a photonic integrated Si3N4 microcomb to achieve sub-ns switching along with the 25-Gbps non-return-to-zero and 50-Gbps four-level pulse amplitude modulation burst mode data transmission. And they used a photonic integrated circuit comprising an Indium phosphide-based SOA array and an arrayed waveguide grating […]
Unmasking the magic of superconductivity in twisted graphene
Science Daily October 20, 2021 An international team of researchers (USA – Princeton University, Japan) combined tunnelling and Andreev reflection spectroscopy with the scanning tunnelling microscope to observe several key experimental signatures for unconventional superconductivity in magic angle twisted bilayer graphene (MATBG). They showed that the tunnelling spectra below the transition temperature Tc are inconsistent with those of a conventional s-wave superconductor, but rather resemble those of a nodal superconductor with an anisotropic pairing mechanism. They observed a large discrepancy between the tunnelling gap which far exceeds the mean-field BCS ratio, and the gap extracted from Andreev reflection spectroscopy. The […]
Using quantum Parrondo’s random walks for encryption
Phys.org October 15, 2021 Quantum game theory has stimulated some interest in recent years with the advancement of quantum information theory. This interest has led to a resurgence of quantum Parrondo’s games. With two losing games combining to give a winning game, this paradoxical idea is known as Parrondo’s paradox. Researchers in Singapore used chaotic switching between the two losing quantum games, to show that it is possible to achieve Parrondo’s paradox involving a quantum walker playing two-sided quantum coin tossing games. They showed that the framework of chaotic switching in quantum coin tosses can be applied to encryption. This […]
What drove the invention of military technologies?
Phys.org October 20, 2021 An international team of researchers (UK, Canada, Russia, USA – Field Museum of Natural History, Evolution Institute, Austria) analyzed the evolution of key military technologies in a sample of pre-industrial societies world-wide covering almost 10,000 years of history using Seshat: Global History Databank. They empirically tested previously speculative theories that proposed world population size, connectivity between geographical areas of innovation and adoption, and critical enabling technological advances, such as iron metallurgy and horse riding, as central drivers of military technological evolution. They found that all these factors are strong predictors of change in military technology, whereas […]
Top 10 Science and Technology Inventions for the Week of October 15, 2021
01. First-in-Class Nerve Agent Antidote Crosses Blood-Brain Barrier to Aid Central Nervous System 02. A rare feat: Material protects against both biological and chemical threats 03. An electrolyte design strategy for making divalent metal batteries 04. Photon-phonon breakthrough 05. Researchers develop sensitive new way of detecting transistor defects 06. Energetic ferroelectrics 07. A highly simplified way to predict quantum light-matter interactions 08. Storing data as mixtures of fluorescent dyes 09. Novel treatment technology ‘could reduce UK nuclear waste burden’ 10. Research on levitating oil droplets may help reduce air pollution And others… The discovery of red blood cells acting as […]
An electrolyte design strategy for making divalent metal batteries
Phys.org October 8, 2021 Rechargeable magnesium and calcium metal batteries (RMBs and RCBs) are promising alternatives to lithium-ion batteries because of the high crustal abundance and capacity of magnesium and calcium. But they are plagued by sluggish kinetics and parasitic reactions. A team of researchers in the US (USA – University of Maryland, US Army, China) found a family of methoxyethyl-amine chelants that greatly promote interfacial charge transfer kinetics and suppress side reactions on both the cathode and metal anode through solvation sheath reorganization, thus enabling stable and highly reversible cycling of the RMB and RCB full cells with energy […]
The discovery of red blood cells acting as micro-electrodes opens new doors in medical research
Phys.org October 8, 2021 Through intricate experiments with red blood cells an international team of researchers (UK, France) has shown that the voltage appears outside the cell as well. This means that cells effectively act as tiny transmitters, electrically changing the environment around them. Similar results in other types of biological cells could play a significant role in determining new types of medical treatment. They demonstrated that the electrical characteristics of red blood cells exhibit circadian rhythms with peaks coinciding with the time of day when most cardiovascular disease events occur, such as heart attacks and strokes, presenting an important […]
Energetic ferroelectrics
Nanowerk October 14, 2021 A team of researchers in the US (SUNY Buffalo, University of Maryland, US Army Aberdeen Proving Ground) tested if two dissimilar materials – molecular energetic materials and ferroelectrics – can be combined to obtain a chemically driven electrical energy source with high-power density. They designed energetic molecular ferroelectrics consisting of imidazolium cations (energetic ion) and perchlorate anions (oxidizer) and described its thermal wave energy conversion with a specific power of 1.8 kW kg−1. They showed that chemically driven energy generator is a result of the coupling between energetic thermal and shock waves and a pyroelectric effect in molecular […]
First-in-Class Nerve Agent Antidote Crosses Blood-Brain Barrier to Aid Central Nervous System
Global Biodefense October 12, 2021 Chemical weapon nerve agents like Sarin or Novichok typically function by blocking the transmission of messages from the central nervous system to the peripheral nervous system, which controls many processes, including respiration. Historically countermeasures cannot cross the blood-brain barrier, and only protect against damage to the peripheral nervous system. After laboratory and computational testing, a team of researchers in the US (Lawrence Livermore National Laboratory, U.S. Army Medical Research Institute of Chemical Defense (USAMRICD) ) has a compound called “LLNL-02” that protects both the central and peripheral nervous systems against the effects of the nerve agent […]