Phys.org February 8, 2021 Wiring up the transistors of an optical circuit with silicon waveguides is an important requirement to make compact, highly integrated chips. However, silicon is a strong absorber of visible light. To circumvent the absorption issue researchers in Switzerland used high contrast grating consisting of nanometer sized “posts” lined up in such a way that light passing through the posts interferes destructively with light passing between posts making sure that no light can “leak” through the grating. Most of the light gets reflected inside the waveguide. They showed that there was a loss of only 13 percent […]
Author Archives: Hema Viswanath
UMass Amherst team helps demonstrate spontaneous quantum error correction
EurekAlert February 11, 2021 Existing demonstrations of quantum correction codes (QEC) are hardware intensive and prone to introducing and propagating errors. A team of researchers in the US (UMass Amherst, Northwestern University) encoded a logical qubit in Schrödinger cat-like multiphoton states of a superconducting cavity and demonstrated a corrective dissipation process that stabilizes an error-syndrome operator, the photon number parity. Implemented with continuous-wave control fields only, this passive protocol protects the quantum information by autonomously correcting single-photon-loss errors and boosts the coherence time of the bosonic qubit by over a factor of two. QEC is realized in a modest hardware […]
Top 10 Science and Technology Inventions for the Week of February 5, 2021
01. Quantum tunneling in graphene advances the age of terahertz wireless communications 02. Researchers create origami-inspired satellite antennas that can self-fold 03. Researchers create novel photonic chip 04. Researchers demonstrate the potential of a new quantum material for creating two spintronic technologies 05. Researchers design next-generation photodetector 06. Researchers from NUS create ‘whirling’ nano-structures in anti-ferromagnets 07. Terahertz accelerates beyond 5G towards 6G 08. Batteries that can be assembled in ambient air 09. Direct coherent multi-ink printing of fabric supercapacitors 10. Experts ‘scan horizon’ to help prepare governments for next major biosecurity threat And others… AI Predicts Asymptomatic Carriers of […]
AI Predicts Asymptomatic Carriers of COVID-19
IEEE Spectrum February 2, 2021 An international team of researchers (Germany, USA – industry) has developed a machine learning algorithm to determine the likelihood of asymptomatic carriers of the SARS-CoV-2 virus by using interaction-based continuous learning and inference of individual probability (CLIIP) for contagious ranking. It is based on multi-layer bidirectional path tracking and inference searching. The individual directed graph is determined by the appearance timeline and spatial data that can adapt over time, taking into account the incubation period and several features that can represent real-world circumstances, such as the number of asymptomatic carriers present. The model collects the […]
Batteries that can be assembled in ambient air
EurekAlert February 1, 2021 Lithium batteries are typically assembled in a dry room that controls moisture because lithium salts in the electrolytes are highly reactive with moisture, which has a significant effect on the battery performance. Researchers in South Korea fabricated impurity scavenging separator membrane (ISM) using a powerful H2O and HF scavenging material. The material was synthesized by a urethane reaction between porous silica (p-SiO2) and (3-isocynatopropyl) triethoxysilane (ICPTES). The p-SiO2 reaction with ICPTES suppressed the acidification of the electrolyte with water and resulted in maintaining the shape of the SiO2 particles. The multifunctional separator exhibited high capacity retention […]
Direct coherent multi-ink printing of fabric supercapacitors
Phys.org January 29, 2021 Fiber-shaped supercapacitors are a desirable high-performance energy storage technology for wearable electronics. The traditional method for device fabrication is based on a multistep approach to construct energy devices, which can present challenges during fabrication, scalability, and durability. An international team of researchers (China, USA – University of Colorado, Carnegie Mellon University, Singapore) has developed an all-in-one coaxial fiber-shaped asymmetric supercapacitor (FASC) device using direct coherent multi-ink writing, 3-D printing technology by designing the internal structure of the coaxial needles and regulating the rheological property and feed rates of the multi-ink. The device delivered a superior areal […]
Experts ‘scan horizon’ to help prepare governments for next major biosecurity threat
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 […]