Lithium-ion batteries are widely used in portable electronic devices and electric vehicles since their introduction by Sony in 1991. Safety is an important concern since about two billion cells are produced every year but with a one-in-200,000 failure rate. Excessive temperature variations and high temperatures over the melting point of the metallic lithium can cause […]
We are all familiar with the equation of ideal gases: PV = nRT. To deduce this equation, an ideal model of the gas is considered. In this model, gases are composed of particles so tiny compared to the volume of the gas that they can be considered zero-volume points in space, and there are no […]
Chemistry • Condensed matter • Materials • Physics • Quantum physics
Minimizing losses in any kind of electronic device is always important, but it is paramount in nanoelectronics. Still, most of the phenomena that lead to inefficiencies in the operation of these nanodevices are poorly understood. Consider the case of quantum dots. A quantum dot is a nanometric crystalline structure of semiconductor materials. In a quantum […]
When two superconducting materials are separated by a very thin (less than 10-8 m or 10 nanometers) layer of an insulating material at very low temperature some peculiar electrical effects can be detected called Josephson effects. If normal conducting metals are separated by such a barrier in that conditions it is possible for a small […]
We are all familiar with rust. Rust is an iron oxide, usually red, formed by the reaction of iron and oxygen in the presence of water or air moisture, and it is a clear sign of metal corrosion by oxidation. Oxidation is a ubiquitous phenomenon that proceeds via the electrochemical interaction of ambient oxygen molecules […]
The current in a semiconductor consists of two parts: the negatively charged electrons in the conduction band and the positively charged holes in the valence band. Although the number of electrons in the conduction band is equal to the number of holes in the valence band, the two contributions to the current are in general […]
Computer science • Condensed matter • Materials • Physics • Quantum physics
When quantum computing comes, it very likely will rely for the fast storage and processing of information on spintronics. Spintronics (from spin transport electronics) is a branch of technology that specifically makes use of quantum-mechanical spin, and especially of the transport of that spin, in electronic devices. Spin is the part of the total angular […]
It is likely that you have read somewhere that gravity is much weaker than the electromagnetic interaction. And it is true: for the electron and the proton gravity is 39 orders of magnitude weaker. Still what governs the movement of moons, planets, stars and galaxies is gravity; even the existence of dark matter is deduced […]
Graphene is a material with outstanding electronic characteristics. Many of them arise from the cone-like dispersion of charge carriers near the Fermi level (at which the occupation probability of energy levels is 0.5), where electrons behave as relativistic Dirac fermions, i.e., as if they had no mass. This excellent video from toutestquantique.fr summarizes them very […]
The exotic properties of layered materials have become a major focus of scientific research. The most famous member of this group is graphene which serves as a building block for few layered graphene and graphite as well as for single- and multi-walled carbon nanotubes. Here, each layer is an one-atom thick hexagonal sheet of sp […]