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 […]
In nanophysics one is dealing with physical systems that are formed of parts consisting of a relatively small number of atoms; these systems are typically less than 100 nm in size. As a consequence quantum and surface effects are extremely important. The subject can be traced back to a remarkably visionary and famous talk given […]
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 […]
No matter how the layout of the periodic table may be, there are elements that are always grouped together. This is easy to understand; let’s take for example the standard form of the table (due to H.G. Deming). In this layout each group, each vertical column in the table, has more significant periodic trends than […]
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 […]
Superconductors are a particularly strange kind of metal. What makes them different is their behavior at very low temperatures – extremely low, that is, close to absolute zero. Basic thermodynamics dictates that in this regime we should expect all motion to cease, the constituents of the material being frozen at fixed positions. And with no […]
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 […]