IEEE Spectrum December 29, 2020 The logic circuits behind just about every digital device today rely on a pairing of NMOS and PMOS. Researchers at Intel showed a different way: stacking the pairs so that one is atop the other. The scheme effectively cut the footprint of a simple CMOS circuit in half, meaning a potential doubling of transistor density on future ICs. The main part of the transistor consisting of a vertical fin of silicon as it does today, the nanosheet’s channel region consists of multiple, horizontal, nanometers-thin sheets stacked atop one another. They built an inverter using these […]
Author Archives: Hema Viswanath
Machine-learning models of matter beyond interatomic potentials
EurekAlert January 7, 2021 The electronic density of states (DOS) quantifies the distribution of the energy levels that can be occupied by electrons in a quasiparticle picture and is central to modern electronic structure theory and underpins the computation and interpretation of experimentally observable material properties such as optical absorption and electrical conductivity. An international team of researchers (Switzerland, UK) studied the configurations of silicon spanning a broad set of thermodynamic conditions, ranging from bulk structures to clusters and from semiconducting to metallic behavior and compared different approaches to represent the DOS, and the accuracy of predicting quantities such as […]
Neither liquid nor solid
Science Daily January 5, 2021 Most experiments involving colloidal suspensions have relied on spherical colloids. Using polymer chemistry researchers in Germany manufactured small plastic particles, stretching, and cooling them until they achieved their ellipsoid forms and then placed them in a suitable solvent. They found that due to their distinct shapes their particles had orientation which gave rise to entirely new and previously unstudied kinds of complex behaviours. By changing particle concentrations in the suspensions, and tracking both the translational and rotational motion of the particles using confocal microscopy, they observed two competing glass transitions — a regular phase transformation […]
Old silicon learns new tricks
Science Daily January 6, 2021 Using a combination of standard dry etching and chemical etching an international team of researchers (Japan, China) fabricated arrays of pyramid-shaped silicon nanostructures. An ultrathin layer of iron was deposited onto the silicon to impart unusual magnetic properties. The pyramids’ atomic-level orientation defined the orientation and thus the properties-of the overlaying iron. Epitaxial growth of iron enabled shape anisotropy of the nanofilm. The curve for the magnetization as a function of the magnetic field was rectangular-like shaped but with breaking points which were caused by asymmetric motion of magnetic vortex bound in pyramid apex. They […]
On the road to invisible solar panels: How tomorrow’s windows will generate electricity
EurekAlert January 5, 2021 The transparent photovoltaic cell (TPC) is an invisible solar cell bypassing the visible range light while absorbing harmful UV light to generate electric power. An international team of researchers (South Korea, India, Viet Nam) fabricated the TPC using TiO2 as the n-type semiconductor to serve as the UV light absorber. Above TiO2 layer, p-type NiO is deposited for a high transmittance (>57%) for the visible light. The two different metal-oxide species are employed to make a transparent heterojunction. TPC is transparent to human eyes and which would serve as an invisible power source for the window […]
Parts of The Amazon Rainforest Are Heading For Collapse by 2064, New Report Shows
Science Alert January 1, 2021 Researchers at the University of Florida reviewed recent research on the Amazon rainforest to reach a grim conclusion. Lengthening dry seasons will soon no longer allow the rainforest canopies the five years they need in between dry seasons to recover from fires, allowing flammable grasses and shrubs to take over. Southern Amazonia can expect to reach a tipping point sometime before 2064 at the current rate of dry season lengthening. Like dominos, models predict once 30-50 percent deforestation is reached in the south, this will decrease the amount of rain by up to 40 percent […]
Scrambled supersolids: Soft form of a solid discovered
Science Daily January 4, 2021 An international team of researchers (Austria, Switzerland) created supersolids using ultracold quantum gases of highly magnetic lanthanide atoms. This state of matter is solid and liquid at the same time. Due to quantum effects, a very cold gas of atoms can spontaneously develop both a crystalline order of a solid crystal and particle flow like a superfluid quantum liquid. A dipolar supersolid can be imagined as a chain of quantum droplets which communicate with each other via a superfluid background bath. They found that if the superfluid bath between the droplets is drained by control […]
World’s fastest optical neuromorphic processor
Science Daily January 7, 2021 Convolutional neural networks have been central to the artificial intelligence revolution, but existing silicon technology increasingly presents a bottleneck in processing speed and energy efficiency. An international team of researchers (Australia, China, Canada) has demonstrated an optical neuromorphic processor for artificial intelligence which operates faster than 10 trillion operations per second (TeraOPs/s) and is capable of processing ultra-large scale data, enough to achieve full facial image recognition, something that other optical processors have been unable to accomplish. The system uses a single processor and was achieved using a new technique of simultaneously interleaving the data […]
Top 10 Science and Technology Inventions for the Week of January 01, 2021
01. New quantum nanodevice can simultaneously act as a heat engine and a refrigerator 02. Extremely energy efficient microprocessor developed using superconductors 03. Metasurface enabled quantum edge detection 04. Powering up stretchy technology 05. Researchers achieve sustained, high-fidelity quantum teleportation 06. Shapeshifting crystals: Varying stability in different forms of gallium selenide monolayers 07. Stretching diamond for next-generation microelectronics 08. Tiny terahertz laser is the first to reach three key performance goals at once 09. Top MIT research stories of 2020 10. Atomic-scale nanowires can now be produced at scale
Atomic-scale nanowires can now be produced at scale
Phys.org December 24, 2020 Transition-metal chalcogenide (TMC) nanowires, which are one-dimensional structures having three-atom diameters and van der Waals surfaces, have been reported to possess a 1D metallic nature with great potential in electronics and energy devices. To mass produce TMC researchers in Japan have demonstrated a wafer-scale synthesis of highly crystalline transition-metal telluride nanowires by chemical vapor deposition. The technique enables formation of either aligned, atomically thin two-dimensional (2D) sheets or random networks of three-dimensional (3D) bundles, both composed of individual nanowires. These nanowires exhibit an anisotropic 1D optical response and superior conducting properties. The findings not only shed […]