Science Daily September 20, 2021 Researchers in Japan have developed superconducting qubits based on NbN/AlN/NbN epitaxial Josephson junctions on silicon substrates which promise to overcome the drawbacks of qubits based on Al/AlOx/Al junctions. The all-nitride qubits have great advantages such as chemical stability against oxidation, resulting in fewer two-level fluctuators, feasibility for epitaxial tunnel barriers that reduce energy relaxation and dephasing, and a larger superconducting gap of ~5.2 meV for NbN, compared to ~0.3 meV for aluminum, which suppresses the excitation of quasiparticles. By replacing conventional MgO by a silicon substrate with a TiN buffer layer for epitaxial growth of […]
BD21 Biosensor Redesign: DHS Seeks Contractors to Improve Urban BioThreat Classification Sensor
Global Biodefense September 3, 2021 The Biodefense for the 21st Century (BD21) program is working to design, develop, and deploy networked detection systems that continuously monitor the air, collect real-time data, and employ data analytics to detect anomalies. DHS has identified the need for further research and development of commercially available biological detection and presumptive identification technologies to enable timely detection and characterization of airborne bio-threats. The biosensors will be deployed both in indoor and outdoor urban environments to conduct real-time monitoring of biological threats. The redesign is to occur over 15 months and will take place in 2 phases. […]
Chinese scientists report starch synthesis from carbon dioxide
Phys.org September 23, 2021 Starches, a storage form of carbohydrates, are a major source of calories in the human diet and a primary feedstock for bioindustry. Researchers in China designed an artificial route consisting of 11 core reactions to convert CO2 into starch with an efficiency 8.5-fold higher than starch biosynthesis in maize. They integrated chemical and biological catalytic modules to utilize high-density energy and high-concentration CO2. If the overall cost of the process can be reduced to a level economically comparable with agricultural planting in the future, it is expected to save more than 90% of cultivated land and […]
Deadly virus’s pathway to infect cells identified
Science Daily September 23, 2021 Rift Valley fever virus (RVFV) is a zoonotic pathogen with pandemic potential. RVFV entry is mediated by the viral glycoprotein (Gn), but host entry factors remain poorly defined. An international team of researchers (USA – Washington University, University of Pittsburgh, Harvard University, MIT, Canada) conducted genome-wide CRISPR screen and identified low-density lipoprotein receptor-related protein 1 (mouse Lrp1/human LRP1), heat shock protein (Grp94), and receptor-associated protein (RAP) as critical host factors for RVFV infection. RVFV Gn directly binds to specific Lrp1 clusters and is glycosylation independent. Exogenous addition of murine RAP domain 3 (mRAPD3) and anti-Lrp1 […]
Fiber tracking method delivers important new insights into turbulence
Phys.org September 17, 2021 To measure turbulent flows the movement of tracers that are added to the fluid are tracked. The tracers spread over time, they move far apart, and every particle moves independently. To overcome these issues an international team of researchers (Switzerland, Italy, Sweden) used fibers instead of tracer particles. They created a computer simulation and added rigid fibers of different lengths, which kept the ends of each fiber apart at a fixed distance. By tracking how each fiber moved and rotated within the fluid over time, the researchers were able to build up a picture that encompassed […]
Harnessing drones, geophysics and artificial intelligence to root out land mines
Phys.org September 20, 2021 Mines are challenging for clearance operations due to their wide area of impact upon deployment, small size, and random minefield orientation. In their previous work a team of researchers in the US (Columbia University, Binghamton University) focused on developing reliable unpiloted aerial systems (UAS) capable of detecting and identifying individual elements of PFM-1 minefields to rapidly assess wide areas for landmine contamination, minefield orientation, and possible minefield overlap. In their most recent proof-of-concept study they designed and deployed a machine learning workflow involving a region-based convolutional neural network (R-CNN) to automate the detection and classification process. […]
Melting of polar ice shifting Earth itself, not just sea levels
Phys.org September 22, 2021 The loss of melting ice from land masses such as Greenland and Antarctica are causing the planet’s crust to warp slightly, even in spots more than 1,000 kilometres from the ice loss. A team of researchers in the US (Harvard University, Columbia University) analyzed satellite data on melt from 2003 to 2018 and studied changes in Earth’s crust to measure the shifting of the crust horizontally. They found that in some places the crust was moving more horizontally than it was lifting. They demonstrated that mass changes in the Greenland Ice Sheet and high latitude glacier […]
The nanophotonics orchestra presents: Twisting to the light of nanoparticles
Science Daily September 20, 2021 In 3D isotropic liquids, optical third-harmonic generation is forbidden, with circularly polarized light (CPL). Yet the associated nonlinear susceptibility directly influences the optical properties at the fundamental frequency by intensity dependence. An international team of researchers (UK, Germany) has revealed the hidden third-harmonic optical properties upon circularly polarized light (CPL) by demonstrating a new effect, in hyper-Rayleigh scattering. The intensity of light scattered at the third-harmonic frequency of the CPL incident light depends on the chirality of the scatterers. It is referred to as third harmonic (hyper) Rayleigh scattering optical activity (THRS OA) and was […]
New optical ‘transistor’ speeds up computation up to 1,000 times, at lowest switching energy possible
Phys.org September 22, 2021 Based on light-matter coupling, an international team of researchers (Russia, Switzerland, Germany, UK) created an optical switch which in a proof-of-principle demonstration achieved switching with just one photon at room temperature. The switch could act as a component that links devices by shuttling data between them in the form of optical signals, and serve as an amplifier, boosting the intensity of an incoming laser beam by a factor of up to 23,000. The device relies on two lasers to set its state to “0” or “1” and to switch between them. The switching occurs inside a […]
A new way to control qubits
Phys.org September 22, 2021 A team of researchers in the US (NIST, University of Colorado, Lawrence Livermore National Laboratory, University of Oregon, UT Austin) demonstrated high-fidelity laser-free universal control of two trapped-ion qubits by creating both symmetric and antisymmetric maximally entangled states with fidelities of 1+0−0.0017 and 0.9977+0.0010−0.0013, respectively (68 per cent confidence level), corrected for initialization error. They used a scheme based on radiofrequency magnetic field gradients combined with microwave magnetic fields that is robust against multiple sources of decoherence and usable with essentially any trapped ion species. The scheme has the potential to perform simultaneous entangling operations on […]