Imagine you want to study the biology of an animal that no one has been able to capture. First, you devise a way of trapping it, then a method of calming it down so that you can manipulate it. This is exactly what David Wineland did, but his long-sought prey was not an animal, but […]
Chemistry • Condensed matter • Energy • Materials • Physics
The German mineralogist Gustav Rose (1798 – 1873) made important contributions in the fields of petrology and crystallography. He was the first to use a reflective goniometer in Germany and developed a particular interest in the relationship between the crystalline form and the physical properties of minerals. As a consequence, he contributed significantly to the […]
Anyone who has studied, even superficially, some thermodynamics has encountered the word adiabatic very early. This is because adiabatic processes are extremely useful to understand the basics of the field. An adiabatic process is any process that occurs without heat (or matter) entering or leaving a system. In general, an adiabatic change involves a fall […]
Our universe is not stable according to the currently measured values of the top quark and Higgs particle masses. There is a non-null probability that at any instant in the next billions of years the present “false vacuum” will change to a “true vacuum” by quantum tunneling, destroying all matter, energy and spacetime without any […]
Usually, the concept of exciton is linked to that of nonmetallic crystal: an electron-hole pair in a crystal that is bound in a manner analogous to the electron and proton of a hydrogen atom. It behaves like an atomic excitation (hence the name) that passes from atom to another and may be long-lived. Exciton behaviour […]
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 […]
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 […]