Phys.org November 27, 2019 The universe is governed by four fundamental forces: gravity, electromagnetism and the strong and weak nuclear forces which are a part of the Standard Model of particle physics. But the Standard Model can’t combine with gravity in the way that we thought. Dark matter and dark energy are also problamatic. An international team of researchers (Hungary, the Netherlands) looks at an anomaly in the decay of helium-4 nuclei, and it builds off an earlier study of beryllium-8 decays. That also seems to violate the Standard Model slightly. The fifth force could exist, but we haven’t found […]
A missing link in haze formation
Science Daily November 25, 2019 Particles in the atmosphere that are 2.5 to 10 micrometers in size, can be inhaled, are potentially harming the heart and lungs. Alcohols in general and methanol in particular are believed to play a small role in atmospheric new particle formation (NPF) largely due to the weak binding abilities of alcohols with the major nucleation precursors. An international team of researchers (USA – University of Nebraska, University of Pennsylvania, Finland, China) has identified a catalytic reaction between methanol and sulfur trioxide (SO3) which can have unexpected quenching effects on the NPF process, particularly in dry […]
A momentous view on the birth of photoelectrons
Phys.org December 5, 2019 The creation of photoelectrons through ionisation is one of the most fundamental processes in the interaction between light and matter and in some cases, it is the transfer of linear momentum from photons to electrons which is not well understood. By a time-resolved measurement of linear momentum transfer along the laser pulse propagation direction researchers in Switzerland have shown that the linear momentum transfer to the photoelectron depends on the ionization time within the laser cycle using the attoclock technique. The research opened a new exciting route to explore the very fundamental nature of light-matter interactions…read […]
New tool to predict the global spread of dengue
Science Daily December 4, 2019 According to the World Health Organisation, around half the world’s population is at risk of contracting dengue. International travelers significantly contribute to dengue’s rapid and large-scale spread by importing the disease from endemic into non-endemic countries. Researchers in Australia consider international air travel volumes to construct weighted networks, representing passenger flows between airports. They calculate the probability of passengers being infected with dengue which depends on the destination, duration and timing of travel. The findings shed light onto dengue importation routes and reveal country-specific reporting rates that have been until now largely unknown. The research […]
Novel material switches between electrically conducting and insulating states
Nanowerk December 4, 2019 Researchers at Northwestern University designed the picoscale crystalline structure of molybdenum oxynitride (MoON), to host the phase transition. The researchers found the metal-insulator transition (MIT) occurred near 600 degrees Celsius, revealing its potential for applications in high-temperature sensors and power electronics. They noted multiple design parameters influenced MoON’s phase transition. The inclusion of multiple anions in the material activated the phase transition due to specific electron configurations related to the spatial orientation of electronic orbitals. The findings offer insight into how subtle changes on the nanoscale can be used to control macroscopic behavior, like conductivity, in […]
Quantum dot lasers move a step closer with electric-pumping development
Phys.org November 29, 2019 Colloidal quantum dots (CQDs) are highly promising materials for light amplification. But band-edge state degeneracy demands multiple excitons to achieve population inversion increasing the lasing threshold and limits the gain lifetime. Researchers in Singapore have demonstrated that the amplified spontaneous emission (ASE) threshold is controllable in a device where CQD film is exposed to an external electric field. Specifically, singly charged CQDs lower the threshold due to the preexisting electron in the conduction band, while strongly enhanced Auger recombination in doubly charged CQDs stymies the ASE. According to the researchers the next big challenge in laser […]
Researchers find potential solution to overheating mobile phones
Phys.org November 29, 2019 Widespread applications of magnetic devices require an efficient means to manipulate the local magnetization. An international team of researchers (Singapore, South Korea) has experimentally demonstrated an alternative approach based on magnon currents and achieved magnon-torque–induced magnetization switching in Bi2Se3/antiferromagnetic insulator NiO/ferromagnet devices at room temperature. The magnon currents carry spin angular momentum efficiently without involving moving electrons through a 25-nanometer-thick NiO layer. The magnon torque is sufficient to control the magnetization. This research, which is relevant to the energy-efficient control of spintronic devices, will invigorate magnon-based memory and logic devices…read more. TECHNICAL ARTICLE
Study sheds light on the peculiar ‘normal’ phase of high-temperature superconductors
Science Daily December 3, 2019 In the cuprate high-temperature superconductors, the metallic state above the highest transition temperature is anomalous and is known as the “strange metal.” An international team of researchers (USA – Stanford University, SLAC National Accelerator Laboratory, UC Berkeley, the Netherlands, Japan) studied this state using angle-resolved photoemission spectroscopy. With increasing doping across a temperature-independent critical value pc ~ 0.19, they observed that near the Brillouin zone boundary, the strange metal, characterized by an incoherent spectral function, abruptly reconstructs into a more conventional metal with quasiparticles. Above the temperature of superconducting fluctuations, the pseudo gap also discontinuously […]
Top 10 Science and Technology Inventions for the Week of November 29, 2019
01. Novel memory device can be written on and read out optically or electrically 02. Laser combo opens up futuristic terahertz technology 03. Molecular eraser enables better data storage and computers for AI 04. Toward more efficient computing, with magnetic waves 05. Sniffing Out Errors 06. Black silicon can help detect explosives 07. A Graphene Waveguide For Electrons 08. NASA rockets study why tech goes haywire near poles 09. Gene Editors Could Find New Use as Rapid Detectors of Pathogenic Threats 10. New technology developed to improve forecasting of Earthquakes, Tsunamis And others… How Brexit Will Affect Europe’s Research Infrastructure […]
A Graphene Waveguide For Electrons
American physical Society November 22, 2019 An electron carrying information in its quantum state and acting according to its wave nature can travel though a waveguide, but if multiple modes are available, then the electron can switch between them and lose information. An international team of researchers (USA – MIT, Japan, France) designed a device that includes a graphene flake sandwiched between two insulating sheets. On top of this structure sits a single carbon nanotube. A voltage applied across the CNT induces an electrostatic potential shaped like a rain gutter that extends down into the flake. The potential traps the […]