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 […]
The way a particular reaction proceeds, described in terms of the steps involved, is called mechanism. The study of organic chemistry is, to a great extent, the study of reaction mechanisms and textbooks content both their description and their applications. But something has come to revolutionize the world of mechanisms: surface chemistry. On-surface synthesis is […]
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 […]
Back in 1929, theoretical physicist Hermann Weyl predicted the existence of a new elementary particle with intriguing properties. Specifically, it would be massless (like a photon), have half-integer spin (like an electron) and exist in two mirror-image versions (like left- and right-handed gloves)—a property known as chirality. Imagine there exist a material in which an […]
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 […]
Biology • Biomedicine • Computer science • Nanotechnology • Neuroscience • Physics
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 […]
On 8 October 2013, following the discovery at CERN’s Large Hadron Collider of a new particle that appeared to be the long-sought Higgs boson predicted by the theory, it was announced that Peter Higgs and François Englert had been awarded the 2013 Nobel Prize in Physics. But they were the survivors of the bunch of […]
A region containing a maximum of potential that prevents a particle on one side of it from passing to the other side is called a potential barrier. The net in a tennis court is in a certain way a potential barrier, as the ball needs to have kinetic energy in excess of the height of […]
The concept of vector should be familiar: a quantity for which both magnitude and direction must be stated. This compares with a scalar quantity, where direction is not applicable, like temperature in a precise point. But, what if the magnitude varies with the direction? A vector would be a particular case, with only one direction […]
The so-called van der Waals materials consist of two-dimensional layers bound by weak van der Waals forces. After the isolation of graphene, the field of two-dimensional van der Waals materials has experienced an explosive growth and new families of two-dimensional systems and block-layered bulk materials, such as tetradymite-like topological insulators – electronic materials that have […]