EurekAlert February 3, 2021 A group of 41 academics and figures from industry and government from across the globe submitted 450 questions which were then debated, voted on and ranked to define the 80 most urgent key questions facing the UK government when it comes to biological security. They were subdivided into six categories: bioengineering; communication and behaviour; disease threats (including pandemics); governance and policy; invasive alien species; and securing biological materials and securing against misuse. The questions offer a research agenda for biological security in the UK that can assist the targeting of research resources and inform the implementation […]
The first steps toward a quantum brain
EurekAlert February 1, 2021 The quest to implement machine learning algorithms in hardware has focused on combining various materials to create device functionality. This approach limits functionality, efficiency, complicates scaling and on-chip learning. Researchers in the Netherlands created an atomic spin system that emulates a Boltzmann machine directly in the orbital dynamics of one well-defined material system. They fabricated the prerequisite tunable multi-well energy landscape by gating patterned atomic ensembles using scanning tunneling microscopy. The anisotropic behaviour of black phosphorus, provided plasticity with multi-valued and interlinking synapses that led to tunable probability distributions. They observed an autonomous reorganization of the […]
Quantum tunneling in graphene advances the age of terahertz wireless communications
EurekAlert February 3, 2021 As the radiation frequency is raised to the sub-terahertz (THz) domain, ac-to-dc conversion by conventional electronics becomes challenging and requires alternative rectification protocols. An international team of researchers (Russia, UK) address this challenge by tunnel field-effect transistors made of bilayer graphene (BLG). Taking advantage of BLG’s electrically tunable band structure, they created a lateral tunnel junction and couple it to an antenna exposed to THz radiation. The incoming radiation was then down-converted by the tunnel junction nonlinearity, resulting in high responsivity and low-noise detection. They demonstrated how switching from intraband Ohmic to interband tunneling regime can […]
Research could dramatically lower cost of electron sources
Phys.org February 1, 2021 An international team of researchers (USA – Los Alamos National Laboratory, Rice University, Northwestern University, France) has discovered efficient, regenerative, and low-cost electron sources based on solution-processed halide perovskites thin films when they are excited with light with energy equal to or above their bandgap. They measured a quantum efficiency up to 2.2% and a lifetime of more than 25 h. Importantly, even after degradation, the electron emission could be completely regenerated to its maximum efficiency by deposition of a monolayer of alkali antimonide and tellurides (Cs2Te, K2CsSb, Cs3Sb). The electron emission from halide perovskites can be […]
Researchers create origami-inspired satellite antennas that can self-fold
TechXplore February 4, 2021 Satellites and space vehicles will need to pack more cargo for the long haul. However, certain items, like dish antennas used for wireless communication, pose a challenge since they cannot be very densely packed for flight because of their signature bowl shape. A team of researchers in the US (Texas A&M University, Pennsylvania State University, UC Irvine) has designed, fabricated, and characterized a self-foldable Active Origami Reflector Antenna (AORA) of parabolic form. They used shape memory polymer (SMP) composites and applied origami principles for smooth folds to determine the shape and fold pattern of a planar […]
Researchers create novel photonic chip
Phys.org February 2, 2021 Photonic Digital‐to‐analog converters (DAC) enable a seamless signal conversion with respect to both energy efficiency and short signal delay. Using a silicon photonic chip platform, a team of researchers (Washington University, UCLA) has developed a coherent parallel photonic DAC concept along with a 4‐bit prototype capable of performing as DAC without optic–electric–optic domain crossing. This guarantees a linear intensity weighting among bits when operating at high sampling rates (50 GHz), featuring an exceptional sampling efficiency (> 100 GS −1 ) and small footprint (≈1 mm2) in an 8‐bit implementation. The photonic DAC enables seamless interfaces of next‐generation data processing hardware […]
Researchers demonstrate the potential of a new quantum material for creating two spintronic technologies
Phys.org February 3, 2021 Finding materials with the exact characteristics necessary to fabricate Antiferromagnetic (AFM) spintronics has so far proved to be highly challenging. An international team of researchers (USA – UC Berkeley, Lawrence Berkeley National Laboratory, National High Magnetic Field Laboratory, UCLA, Israel) has identified a new quantum material (Fe1/3 + δNbS2) that could be used to fabricate AFM spintronic devices. They demonstrated that antiferromagnetic switching in the intercalated transition-metal dichalcogenide (TMD)-based compounds have a huge ‘exchange bias’, single-pulse saturation and a significantly lower activation energy. They showed that the coexistence of spin glass and antiferromagnetic order allows a […]
Researchers design next-generation photodetector
EurekAlert February 2, 2021 State-of-the-art LWIR detection technology still suffers from shortcomings such as low photocurrent gain and excess spectral noise. Researchers at Northwestern University used a new approach to design the photodetector using a type-II superlattice, a material system known for its outstanding growth uniformity and exceptional band structure engineering and applied the new material to a heterojunction phototransistor device structure. During testing each part of the photodetector was tuned to use the phototransistor to achieve high optical gain, low noise, and high detectivity. The material’s flexibility allowed for meticulous quantum mechanics-based band structure engineering for the heterostructure design, […]
Researchers from NUS create ‘whirling’ nano-structures in anti-ferromagnets
EurekAlert February 4, 2021 Special magnetic nano-patterns in anti-ferromagnets that are shaped as whirls or vortices would be quite useful, as they are very stable structures and can potentially be moved along magnetic ‘race tracks’ at speeds of a few kilometres per second. To realize anti-ferromagnetic whirls an international team of researchers (Singapore, UK, USA – University of Wisconsin) combined high-quality film synthesis from materials engineering, phase transitions from physics and topology from mathematics. To grow these materials they fired a laser at iron-oxide. By using ultra-short pulses of laser, they created a hot vapour of atomic particles that formed […]
Terahertz accelerates beyond 5G towards 6G
TechXplore February 1, 2021 Researchers in Japan configured a two-channel terahertz transmitter (Tx) by modulating the output of a laser pair with wavelengths in the 1.55-micron band, which was set so that the frequency difference was in the 300-GHz band, with an 8K video signal source using an intensity modulator and converting it into terahertz waves using an ultrafast photodiode. After the wirelessly transmitted terahertz waves were detected by sensitive terahertz coherent receivers (Rxs) using resonant tunnel diodes (RTDs) they were split from the two channels into four channels and connected to an 8K monitor via HDMI cable. Using this […]