Pays.org January 30, 2023 Superconducting FETs operate through continuous tuning of carrier density, but no bistable superconducting FET, which could serve as a new type of cryogenic memory element, has been reported. Recently, gate hysteresis and resultant bistability in Bernal-stacked bilayer graphene aligned to its insulating hexagonal boron nitride gate dielectrics were discovered. An international team of researchers (USA- MIT, Israel) reported the observation of hysteresis in magic-angle twisted bilayer graphene (MATBG) with aligned boron nitride layers. The bistable behaviour coexists alongside the strongly correlated electron system of MATBG without disrupting its correlated insulator or superconducting states. The all-van der […]
Topological acoustic waveguide to help reduce unwanted energy consumption in electronics
Pays.org January 30, 2023 Researchers in Japan have shown that in a honeycomb phononic crystal composed of metallic nanopillars on a LiNbO3 substrate, the topological surface acoustic wave (SAW) mode inhabits the edge of the honeycomb phononic crystal in spite of the hybridization with the internal acoustic modes of the substrate. Pulse-type microwave impedance microscopy showed gigahertz topological edge mode between two mutually inverted topological phononic crystals. A frequency-dependent image showed that the edge mode evolves as the bulk SAW modes are suppressed owing to the energy gap formation, consistent with the topological nature. According to researchers the realization of a […]
DARPA Team Begins Work on Field Deployable Whole Blood Equivalent
DARPA January 31, 2023 DARPA’s Fieldable Solutions for Hemorrhage with bio-Artificial Resuscitation Products (FSHARP) program aims to develop a field-deployable, shelf-stable whole blood equivalent that can be used to resuscitate trauma patients when donated blood products are not available. DARPA selected the University of Maryland to lead this effort with support from several universities and industries. Their plan is to integrate multiple bio-artificial and synthetic components to deliver oxygen, stop bleeding, and replace volume—key therapeutic functions of whole blood in resuscitation. They will evaluate efficacy and safety in increasingly complex and realistic trauma models and intend to develop strategies for […]
Physicists observe rare resonance in molecules for the first time
MIT News February 1, 2023 Whether collisional resonances exist for ultracold ground-state molecules has been debated owing to the possibly high density of states and/or rapid decay of the resonant complex. An international team of researchers (USA MIT, University of Nevada, Canada) reports a very pronounced and narrow (25 mG) Feshbach resonance in collisions between two triplet ground-state NaLi molecules. This molecular Feshbach resonance has two special characteristics. First, the collisional loss rate is enhanced by more than two orders of magnitude above the background loss rate, which is saturated at the p-wave universal value, owing to strong chemical reactivity. Second, the resonance is located at a magnetic field where […]
Seawater split to produce ‘green’ hydrogen
Science Daily February 1, 2023 The use of vast amounts of high-purity water for hydrogen production may aggravate the shortage of freshwater resources. Seawater is abundant but must be desalinated before use in typical proton exchange membrane (PEM) electrolysers. An international team of researchers (China, Australia, USA – Kent State University) has demonstrated direct electrolysis of real seawater that has not been alkalised nor acidified, achieving long-term stability exceeding 100 h at 500 mA cm−2 and similar performance to a typical PEM electrolyser operating in high-purity water. This was done by introducing a Lewis acid layer (for example, Cr2O3) on transition metal oxide catalysts […]
Creating ‘ghostly mirrors’ for high-power lasers
Phys.org January 31, 2023 High power lasers have become useful scientific tools, but their large size is determined by their low damage-threshold optical media. A more robust and compact medium for amplifying and manipulating intense laser pulses is plasma. An international team of researchers (UK, Germany, Portugal) has demonstrated, experimentally and through simulations, that few-millijoule, ultra-short seed pulses interacting with 3.5-J counter-propagating pump pulses in plasma, stimulate back-scattering of nearly 100 mJ pump energy with high intrinsic efficiency, when detuned from Raman resonance. This is due to scattering off a plasma Bragg grating formed by ballistically evolving ions. Electrons are […]
Top 10 Science and Technology Inventions for the Week of January 27, 2023
01. New shield blocks electromagnetic interference while allowing wireless optical signals 02. Novel method helps recover obscured images 03. Photonic hopfions: Light shaped as a smoke ring that behaves like a particle 04. Scientists demonstrate quantum recoil for the first time, paving the way for precise X-ray imaging 05. Scientists observe ‘quasiparticles’ in classical systems for the first time 06. Approaching the terahertz regime 07. Building off the ‘anti-laser,’ researchers create a device that directs waves. 08. Electronic nose: Sensing the odor molecules on graphene surface layered with self-assembled peptides 09. GHz burst mode femtosecond laser pulses can create unique […]
Approaching the terahertz regime
Science Daily January 19, 2023 Tunnelling magnetoresistance (TMR) is considered to be proportional to spin polarization at the interface and has been studied primarily in ferromagnets. An international team of researchers (Japan, Canada) observed TMR in an all-antiferromagnetic tunnel junction consisting of Mn3Sn/MgO/Mn3Sn. They made measurements using a Fe/MgO/Mn3Sn MTJ and showed that the sign and direction of anisotropic longitudinal spin-polarized current in the antiferromagnet can be controlled by octupole direction. They measured a TMR ratio of around 2% at room temperature, which arises between the parallel and antiparallel configurations of the cluster magnetic octupoles in the chiral antiferromagnetic state. […]
Building off the ‘anti-laser,’ researchers create a device that directs waves.
Phys.org January 26, 2023 Building off a breakthrough “anti-laser,” an international team of researchers (France, USA – Yale University) has developed a system that can direct light and other electromagnetic waves for signal processing without any unwanted signal reflections. Instead of transducing it into another form of energy, the device redirected to specific channels. It could either all go into chosen output channels or some of it could be absorbed and the rest go into the output channels. In the next step, they want to make a similar device where the absorption is negligible, so that all the energy is […]
Electronic nose: Sensing the odor molecules on graphene surface layered with self-assembled peptides
Science Daily January 19, 2023 Researchers in Japan designed and developed three new peptides for graphene biosensors that can detect odor molecules to perform two main functions — acting as a biomolecular scaffold for self-assembly on a graphene surface and functioning as a bio-probe to bind the odor molecules. They showed that the peptides uniformly covered the graphene surface with the thickness of a single molecule. When representative odor molecules were injected into the functionalized graphene field-effect transistors (GFETs), graphene conductivity reduced indicating the binding of the odor molecules. The odor molecules gave rise to distinct signatures confirming that the […]