Phys.org July 1, 2022 An international team of researchers (Germany, UC Irvine) developed a microscopic theory for the 2D spectroscopy of one-dimensional topological superconductors. They considered a ring geometry of an archetypal topological superconductor with periodic boundary conditions, bypassing energy-specific differences caused by topologically protected or trivial boundary modes that are hard to distinguish. They showed numerically and analytically that the cross-peak structure of the 2D spectra carries unique signatures of the topological phases of the chain. According to the researchers their work reveals how 2D spectroscopy can identify topological phases in bulk properties…read more. TECHNICAL ARTICLE
These energy-packed batteries work well in extreme cold and heat
EurekAlert July 4, 2022 Researchers at UC San Diego have developed an electrolyte that is not only versatile and robust throughout a wide temperature range, but also compatible with a high energy anode and cathode. It is made of a liquid solution of dibutyl ether mixed with a lithium salt, and compatible with a lithium-sulfur battery. The electrolyte helps improve both the cathode side and anode side while providing high conductivity and interfacial stability. They engineered the sulfur cathode to be more stable by grafting it to a polymer. In tests, the proof-of-concept batteries retained 87.5% and 115.9% of their […]
Found: The ‘holy grail of catalysis’ turning methane into methanol under ambient conditions using light
Science Direct June 30, 2022 Partial oxidation of methane (CH4) to methanol (CH3OH) lifts the energy density and drives the production of numerous chemicals. In nature, this is achieved by methane monooxygenase with di-iron sites, which is extremely challenging to mimic in artificial systems due to the high dissociation energy of the C–H bond in CH4 and facile over-oxidation of CH3OH to CO and CO2. An international team of researchers (UK, China, USA – University of Chicago, Oak Ridge National Laboratory, Japan) has achieved the direct photo-oxidation of CH4 over mono-iron hydroxyl sites immobilized within a metal–organic framework, PMOF-RuFe(OH). Under […]
A four-stroke engine for atoms
Phys.org July 6, 2022 Electric control of magnetism and magnetic control of ferroelectricity can improve the energy efficiency of magnetic memory and data-processing devices. However, the necessary magnetoelectric switching is hard to achieve, and requires more than just a coupling between the spin and the charge degrees of freedom. An international team of researchers (Italy, Austria, USA – Rutgers University, the Netherlands) showed that an application and subsequent removal of a magnetic field reverses the electric polarization of the multiferroic GdMn2O5, thus required two cycles to bring the system back to the original configuration. During this unusual hysteresis loop, four […]
Hearing better with skin than ears
Science Daily July 1, 2022 Previously reported wearable sensors for smart human–machine interaction have limited sound-sensing quality as a consequence of a poor frequency response and a narrow acoustic-pressure range. Researchers in South Korea have developed a skin-attachable acoustic sensor that has higher sensing accuracy in wider auditory field than human ears, with flat frequency response (15–10 000 Hz) and a good range of linearity (29–134 dBSPL) as well as high conformality to flexible surfaces and human skin. They exploited the low residual stress and high processability of polymer materials in a diaphragm structure designed using acousto-mechano-electric modeling to achieve the […]
Laser writing may enable ‘electronic nose’ for multi-gas sensor
Science Daily June 30, 2022 Laser-induced thermal voxels (LITV) offer a facile platform to directly integrate nanocrystalline metal oxide and mixed metal oxide materials onto heating platforms, with access to a wide variety of compositions and morphologies including many transition metals and noble metals. Researchers at Pennsylvania State University combined laser writing and responsive sensor technologies to fabricate the first highly customizable microscale gas sensing devices. They investigated the sensing performance of a representative set of n-type and p-type LITV-deposited metal oxides and their mixtures (CuO, NiO, CuO/ZnO, and Fe2O3/Pt) in response to reducing and oxidizing gases (H2S, NO2, NH3, […]
Magnetic spins that ‘freeze’ when heated: Nature in the wrong direction
Nanowerk July 4, 2022 An international team of researchers (the Netherlands, Sweden) observed an unusual magnetic transition in elemental neodymium where, with increasing temperature, long-range multiply periodic ‘multi-Q’ magnetic order emerged from a self-induced spin glass. They characterized the local order of a previously reported spin glass phase and quantified the emergence of long-range multi-Q order with increasing temperature. Using the analysis tools they developed, they determined the glass transition temperature from measurements of the spatially dependent magnetization. They compared these observations with atomistic spin dynamics simulations to reproduce the qualitative observation of a phase transition from a low-temperature spin […]
Nanoparticle vaccine protects against a spectrum of COVID-19-causing variants and related viruses
Phys.org July 5, 2022 An international team of researchers (USA – Caltech, NIAID, University of Washington, Stanford, industry, the Rockefeller University, UK) chose eight different SARS-like betacoronaviruses—including SARS-CoV-2 along with seven related animal viruses that could have potential to start a pandemic in humans—and attached fragments from those eight viruses onto the nanoparticle scaffold. The idea was that such a vaccine could induce the body to produce antibodies that broadly recognize SARS-like betacoronaviruses to fight off variants in addition to those presented on the nanoparticle by targeting common characteristics of viral RBDs. In mice, antibodies to the SARS-CoV-2 RBD were […]
Novel imaging method developed for fast-moving objects
Phys.org July 5, 2022 When single-pixel imaging (SPI) is applied to imaging the dynamic object, severe motion blur in the restored image tends to appear. Researchers in China used a small amount of information detected by the single-pixel detector to locate and track the moving targets. With the increase of detection information over time, imaging of fast-moving objects and motion blur correction were realized synchronously. The technology fully exploits the characteristics of single-pixel detection and realizes rapid positioning, clear imaging, and recognition of fast-moving targets according to the characteristics of the system’s detection information data stream. The proposed technology roadmaps […]
Photon-controlled diode: An optoelectronic device with a new signal processing behavior
Phys.org July 1, 2022 The photodetector is a key component in optoelectronic integrated circuits. Although there are various device structures and mechanisms, the output current changes either from rectified to fully-on or from fully-off to fully-on after illumination. According to researchers in China the device that changes the output current from fully-off to rectified should be possible. They designed a photon-controlled diode based on a n/n− molybdenum disulfide junction. Schottky junctions formed at the cathode and anode either prevent or allow the device to be rectifying, so that the output current of the device changes from fully-off to rectified. By […]