Category archives: Physics

Since the discovery of graphene, a wide diversity of atomic-layer-thick, two-dimensional (2D) materials with varied properties have emerged. Of particular interest are those that exhibit semiconducting behavior, such as hexagonal boron nitride (hBN). hBN is isoelectronic to graphene and has also a honeycomb lattice formed by alternating nitrogen and boron atoms, but in contrast to […]

So-called “valleytronics” is a new type of electronics that could lead to faster and more efficient computer logic systems and data storage chips in next-generation devices. Valley electrons are so named because they carry a valley degree of freedom, a pseudospin. This is a new way to harness electrons for information processing that’s in addition […]

With the possible exception of Avogadro’s number, which was in reality defined and made popular by Stanislao Cannizzaro, many things in the sciences are usually named after the person who makes them popular. The Seebeck effect is an example. Originally discovered in 1794 by Alessandro Volta, it is named after Thomas Johann Seebeck, who in […]

In 1873, the microscopist Ernst Abbe stipulated a physical limit for the maximum resolution of traditional optical microscopy: 0.2 micrometers, or 200 nanometers (the shortest wavelength for visible light, the extreme limit of violet). This meant that scientists could distinguish whole cells, as well as some parts of the cell called organelles. However, they would […]

Wildfires are a major problem with a strong impact on human life, property and the environment, Global warming and a legacy of poor management are the forces behind the increase in their occurrence and in their magnitude measured in extension. In 2017, an unusual number of extensive and severe wildfires occurred in many parts of […]

Experiments performed in 1909 by Geiger and Marsden, also called Rutherford gold foil experiment because Rutherford was their supervisor, led to the discovery of nuclear structure in the atom: the nucleus of the atom is its central core and contains most of its mass and the nucleus is positively charged. Further research during the next […]

Common glass, used in windows or bottles, for example, is made by heating a mixture of calcium oxide (lime), sodium carbonate (soda), and silicon (IV) oxide (sand), resulting in a calcium silicate. This silicate is not a crystal but a solid in which atoms are positioned at random and have no long-range ordered pattern. These […]

Spacecraft components potentially exposed to different ionic projectiles in space, new materials used in new energy systems or healthy tissues exposed to cancer therapies are all instances where a full comprehension of how the energy of the incoming ions is dissipated by the matter in the target is of paramount importance. Besides, the dissipative processes […]

The revolutionary theory of topological quantum chemistry , a description of the universal global properties of all possible band structures and materials, diagnoses topological phases based on elementary band representations. A set of bands is topological if it lacks an “atomic limit” that obeys the crystal symmetry (and time reversal, if desired): formally, an atomic […]

Chemists have a range of different spectroscopic techniques to study organic molecules. All of these techniques are based on spectra generated by a range of electronic transitions and vibrations, key excitations in matter, the study of which provides information about characteristics of materials and, therefore, allow their identification. In this context, one of those spectroscopic […]