Science Daily April 5, 2021 An international team of researchers (USA – UC Irvine, UC Berkeley, Lawrence Berkeley National Laboratory, the Netherlands) projected how lightning in high-latitude boreal forests and Arctic tundra regions will change across North America and Eurasia as the climate continues warming and Arctic weather during summertime will be closer to those seen today far to the south, where lightning storms are more common. Looking at over-twenty-year-old NASA satellite data on lighting strikes in northern regions they constructed a relationship between the flash rate and climatic factors. They estimated a significant increase in lightning strikes as a result […]
New computing algorithms expand the boundaries of a quantum future
Phys.org April 6, 2021 Researchers at the Fermi National Accelerator Laboratory have developed two new algorithms that build upon existing work to in the field to further diversify the types of problems quantum computers can solve. To get around the probabilistic nature of superpositions the researchers developed the non-Boolean quantum amplitude amplification algorithm which is open to more tasks. A second algorithm they introduced dubbed the quantum mean estimation algorithm allows scientists to estimate the average. Both algorithms do away with having to reduce scenarios into computations with only two types of output, and instead allow for a range of […]
A new, positive approach could be the key to next-generation, transparent electronics
EurekAlert April 5, 2021 Wide-bandgap p-type oxides have carrier mobilities that are one to two orders of magnitude lower due to strong carrier localization near their valence band edge. Researchers in Australia have grown bilayer beta tellurium dioxide (β-TeO2) through the surface oxidation of a eutectic mixture of tellurium and selenium. It is theoretically proposed as a high-mobility p-type semiconductor. The isolated β-TeO2 nanosheets are transparent and have a direct bandgap of 3.7 eV. Field-effect transistors based on the nanosheets exhibit p-type switching with an on/off ratio exceeding 106 and a field-effect hole mobility of up to 232 cm2 V−1 s−1 at room temperature. […]
Qubits composed of holes could be the trick to build faster, larger quantum computers
Phys.org April 2, 2021 Strong spin-orbit interactions make hole quantum dots central for scalable quantum computation. Therefore it is important to establish to what extent spin-orbit coupling exposes qubits to electrical noise, facilitating decoherence. Taking Ge as an example an international team of researchers (Australia, Canada) has shown that group IV gate-defined hole spin qubits generically exhibit optimal operation points, defined by the top gate electric field, at which they are both fast and long-lived: the dephasing rate vanishes to first order in the electric field noise along with all directions in space, the electron dipole spin resonance strength is […]
Reflecting sunlight could cool the Earth’s ecosystem
Science Daily April 7, 2021 Solar radiation modification (SRM) is one potential approach to partially counteract anthropogenic warming by reflecting a small proportion of the incoming solar radiation to increase Earth’s albedo. An international team of researchers (USA – Michigan State University, Stony Brook University, UC Riverside, City University of New York, industry, UT Rio Grande Valley, University of Minnesota, Oak Ridge National Laboratory, University of Tennessee, University of Minnesota, Rutgers University, Cornell University, Canada, Hong Kong) studied the stratospheric aerosol intervention (SAI), a well-studied and relatively feasible SRM scheme that is likely to have a large impact on Earth’s […]
Researchers report breakthrough that enables practical semiconductor spintronics
Phys.org April 8, 2021 By remote spin filtering of InAs quantum-dot electrons via an adjacent tunnelling-coupled GaNAs spin filter an international team of researchers (Sweden, Finland, Japan) demonstrated successful generation of conduction electron spin polarization exceeding 90% at room temperature without a magnetic field in a non-magnetic all-semiconductor nanostructure, which remains high even up to 110 °C. They also showed that the quantum-dot electron spin can be remotely manipulated by spin control in the adjacent spin filter, paving the way for remote spin encoding and writing of quantum memory as well as for remote spin control of spin–photon interfaces. This work […]
Rise of the robo-writers
Nature Podcast April 4, 2021 Trained on billions of words from books, articles and websites, GPT-3 was the latest in a series of ‘large language model’ AIs that are used by companies around the world to improve search results, answer questions, or propose computer code. However, these large language models are not without their issues. Their training is based on the statistical relationships between the words and phrases, which can lead them to generate toxic or dangerous outputs. Preventing responses like these is a huge challenge for researchers, who are attempting to do so by addressing biases in training data, […]
Scientists achieve single-photon imaging over 200 kilometers
Phys.org April 5, 2021 The operating range of practical single photon lidar systems is limited to about tens of kilometers over the Earth’s atmosphere, mainly due to the weak echo signal mixed with high background noise. By using high-efficiency optical devices for collection and detection, and new noise-suppression technique that is efficient for long-range applications researchers in China have developed a compact coaxial single-photon lidar system capable of realizing 3D imaging at up to 201.5 km. They developed photon-efficient computational algorithms which enabled accurate imaging with as few as 0.44 signal photons per pixel. The research is a significant step […]
Scientists harness chaos to protect devices from hackers
Techxplore.org April 7, 2021 A team of researchers in the US (Ohio State University, industry) created a Physically Unclonable Function (PUF) based on an ultra-fast chaotic network known as a Hybrid Boolean Network (HBN) implemented on a field programmable gate array. PUFs take advantage of tiny manufacturing variations sometimes seen only at the atomic level and used them to create unique sequences of 0s and 1s that researchers in the field call “secrets”. Unlike the current PUFs, the new PUFs have 1077 secrets. They created a complex network in their PUFs using a web of randomly interconnected logic gates that […]
Silencing vibrations in the ground and sounds underwater
EurekAlert April 6, 2021 An international team of researchers (South Korea, Hong Kong) designed an artificial structure that can control not only the domain of underwater sound but also vibration. The research team has presented an underwater stealth metasurface independent from SONAR by controlling the acoustic resonance to absorb the wave. They also confirmed that the wave propagation through a curved plate, such as vibrations, can be drastically altered. Their methodology can achieve the cloaking effect with singularity of infinite refractive index. They designed a thin metasurface to absorb sound waves in broadband (14 kHz to 17 kHz). The metasurface […]