Breaking through the resolution barrier with quantum-limited precision

Science Daily  January 5, 2021 An international team of researchers (USA – Stanford University, Canada, Czech Republic, Spain, Germany) presents a temporal-mode demultiplexing scheme that achieves the ultimate quantum precision for the simultaneous estimation of the temporal centroid, the time offset, and the relative intensities of an incoherent mixture of ultrashort pulses at the single-photon level. They experimentally resolved temporal separations 10 times smaller than the pulse duration, as well as imbalanced intensities. This represents an improvement of more than an order of magnitude over the best standard methods based on intensity detection. The findings could allow significant improvements in […]

The Earth has been spinning faster lately

Phys.org  January 7, 2021 The atomic clocks make it possible to measure the length of a given day down to the millisecond. Since such measurements began, scientists have found that the Earth was slowing its spin very gradually (compensated by the insertion of a leap second now and then) until this past year, when it began spinning faster so much so that some in the field have begun to wonder if a negative leap negative second might be needed this year. Scientists also noted that this past summer, on July 19, the shortest day ever was recorded—it was 1.4602 milliseconds […]

Extremely fast electrochromic supercapacitors

Phys.org  January 7, 2021 Mesoporous metal oxides consisting of fully interconnected network structures with small pores have high surface areas and decreased ion intercalation distances, making them ideal for use in high-performance electrochromic supercapacitors. An international team of researchers (South Korea, Sweden) used an evaporation-induced self-assembly process to deposit a film of tungsten trioxide with pores, where the porous architecture increased the speed of switching and capacitance in the material compared to conventional tungsten trioxide thin films. They developed multifunctional electrochromic supercapacitors based on amorphous mesoporous WO3 films. They attribute its superior performance to its large surface area and amorphous […]

Innovative battery chemistry revolutionizes zinc-air battery

Science Daily  January 4, 2021 An international team of researchers (Germany, China, USA – University of Maryland, US Army Research Laboratory) has developed a zinc-air battery based on an innovative, non-alkaline, aqueous electrolyte bringing a previously unknown reversible zinc peroxide chemistry into the zinc-air battery. The new battery overcomes the high chemical instability, parasitic reactions in the usage of alkaline electrolytes lead to electrochemical irreversibility. The electrolyte which is based on the zinc trifluoromethanesulfonate salt, has several decisive advantages – the zinc anode is used more efficiently with a higher chemical stability and electrochemical reversibility, operate stably for 320 cycles […]

Intel’s Stacked Nanosheet Transistors Could Be the Next Step in Moore’s Law

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 […]

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 […]