The mechanisms resulting in particle acceleration to relativistic energies in space plasmas are an open question. Here, the authors show a reinforced shock acceleration model which enables electrons to efficiently achieve relativistic energies and reveal a low electron injection threshold.
A team of researchers has made a remarkable breakthrough in spintronic technology, achieving a one-directional flow of spin-polarized current in a single-atom layer of thallium-lead alloys.
This advancement not only challenges traditional views of material interaction with light but also heralds the development of ultra-fine, environmentally friendly data storage for the future.
Groundbreaking Discovery in Spintronic Technology.
Protons and other subatomic particles that are subject to the strong nuclear force have a complex structure that involves even more fundamental constituents called quarks and gluons. These quarks and gluons bind under the influence of quantum chromodynamics (QCD). QCD is the theory of strong interaction of quarks and the role of color symmetry.
However, the mechanisms that lead to quarks and gluons combining to form the particles we see in nature are very mysterious and poorly understood. For example, virtual quarks and gluons constantly appear and disappear within our current picture of the dynamics in the proton. So, which quarks and gluons are actually “in” a proton is a difficult question to answer.
Much of the experimental work related to extracting the quark and gluon structure of protons occurs at existing particle accelerators like the Thomas Jefferson National Accelerator Facility and the Relativistic Heavy Ion Collider, and in the future at the Electron Ion Collider.
The amorphous state of matter is the most abundant form of visible matter in the universe, and includes all structurally disordered systems, such as biological cells or essential materials like glass and polymers.
An amorphous material is a solid whose molecules and atoms form disordered structures, meaning that they do not occupy regular, well-defined positions in space.
This is the opposite of what happens in crystals, whose ordered structure facilitates their mathematical description, as well as the identification of those “defects,” which practically control the physical properties of crystals, such as their plastic yielding and melting, or the way an electric current propagates through them.
Stanford researchers have introduced a software tool that accelerates and enhances the analysis of single atom catalysts, offering profound implications for the development of more efficient catalysts.
Catalysts play an essential role in everyday life, from helping bread rise to converting raw materials into fuels more efficiently. Now, researchers at SLAC have developed a faster method to advance the discovery of an exciting new type of catalyst known as single atom catalysts.
The role of catalysts in modern chemistry.
Are there particles that can move faster than light? Harvard astronomer Avi Loeb explores this question and the mysterious role of tachyons.
Researchers at the University of Tokyo have demonstrated that the direction of the spin-polarized current can be restricted to only one direction in a single-atom layer of a thallium-lead alloy when irradiated at room temperature. The discovery defies conventions: single-atom layers have been thought to be almost completely transparent, in other words, negligibly absorbing or interacting with light.
The one-directional flow of the current observed in this study makes possible functionality beyond ordinary diodes, paving the way for more environmentally friendly data storage, such as ultra-fine two-dimensional spintronic devices, in the future. The findings are published in the journal ACS Nano.
Diodes are fundamental building blocks of modern electronics by restricting the flow of currents to only one direction. However, the thinner the device, the more complicated it becomes to design and manufacture these functional components. Thus, demonstrating phenomena that might make such developmental feats possible is critical. Spintronics is an area of study in which researchers manipulate the intrinsic angular momentum (spin) of electrons, for example, by applying light.
The development of sustainable energy sources that can satisfy the world energy demand is one of the most challenging scientific problems. Nuclear fusion, the energy source of stars, is a clean and virtually unlimited energy source that appears as a promising candidate.
The most promising fusion reactor design is based on the tokamak concept, which uses magnetic fields to confine the plasma. Achieving high confinement is key to the development of nuclear fusion power plants and is the final aim of ITER, the largest tokamak in the world currently under construction in Cadarache (France).
The plasma edge stability in a tokamak plays a fundamental role in plasma confinement. In present-day tokamaks, edge instabilities, magnetohydrodynamic waves known as ELMs (edge localized modes), lead to significant particle and energy losses, like solar flares on the edge of the sun. The particle and energy losses due to ELMs can cause erosion and excessive heat fluxes onto the plasma-facing components, at levels unacceptable in future burning plasma devices.
Bimetallic particles, made from a combination of a noble metal and a base metal, have unique catalytic properties that make them highly effective for selective heterogeneous hydrogenation reactions. These properties arise from their distinctive geometric and electronic structures. For hydrogenation to be both effective and selective, it requires specific interactions at the molecular level, where the active atoms on the catalyst precisely target the functional group in the substrate for transformation.
Nanoscale Engineering and Electronic Structure Tuning
Scaling these particles down to nanoscale atomic clusters or single-atom alloys further enhances their catalytic performance. This reduction in size increases surface dispersion and optimizes the use of noble metal atoms. Additionally, these nanoscale changes alter the electronic structure of the active sites, which can significantly influence the activity and selectivity of the reaction. By carefully adjusting the bonding between noble metal single atoms and the base metal host, researchers can create flexible environments that fine-tune the electronic properties needed to activate specific functional groups. Despite these advances, achieving atomically precise fabrication of such active sites remains a significant challenge.
Quantum mechanics has long classified particles into just two distinct types: fermions and bosons.
Now physicists from Rice University in the US have found a third type might be possible after all, at least mathematically speaking. Known as a paraparticles, their behavior could imply the existence of elementary particles nobody has ever considered.
“We determined that new types of particles we never knew of before are possible,” says Kaden Hazzard, who with co-author Zhiyuan Wang formulated a theory to demonstrate how objects that weren’t fermions or bosons could exist in physical reality without breaking any known laws.