When you first study electromagnetism, all the electromagnetic waves you find are plane ones, waves in which the electric and magnetic fields are both orthogonal to the direction of travel of the wave. But this is a mode – the field pattern of the propagating wave – that is somehow ideal, as it exists in […]
Acenes are the class of organic compounds made up of linearly fused benzene rings. The best known of acenes is the compound with three rings, anthracene. The larger representatives, like pentacene (the one with five rings) have potential interest in optoelectronic applications and are actively researched in chemistry and electrical engineering. Starphenes are 2D polyaromatic […]
Isolated atomic planes, two-dimensional (2D) materials, like graphene can be reassembled into designer heterostructures made layer by layer in a precisely chosen sequence. Such heterostructures are often referred to as ‘van der Waals’ and the simpler one is composed of just two layers (bilayer). In 2018, Pablo Jarillo-Herrero, an experimentalist at MIT, found that at […]
Molecules when excited from their ground state (S 0 ) to their lowest electronically excited states often change their electronic structure considerably, which impacts on a range of important molecular properties. For example, the reactivity of a molecule in its excited state often differs markedly from that in its S 0 state. Also, the charge […]
A cement is any of various substances used for bonding or setting to a hard material. A popular one, Portland cement, is a mixture of calcium silicates and aluminates made by heating limestone (CaCO3) with clay (that contains aluminosilicates) in a kiln. The product is then ground to a fine powder. When Portland cement is […]
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 […]
Charge density wave (CDW) is a many-body state of matter in which both lattice and electron density are modulated by a new periodicity. CDW features discrete translational symmetry-breaking, and mostly occurs in low-dimensional materials. Although CDW behaviours have been found in many materials, the underlying mechanism and the driving forces of CDW transition are still […]
During the last decades, the electronics industry has been very successful in pushing forward the advancement of electronic building blocks, but the limit of silicon-based electronic devices especially in terms of miniaturization are almost reached. There are many ideas how to overcome this problem, for example, by adding functionality based on approaches originating from molecular […]
Today, computational chemistry helps the experimental chemist understand experimental data, explore reaction mechanisms or predict completely new molecules. There is no doubt that understanding at the molecular level will ultimately lead to an ab initio process design. Thus, the solution of the quantum mechanical many-electron problem is one of the central problems of physics and […]
Honouring a secular tradition in the physical sciences, that of the Boltzmann constant (created by Planck) and the Avogadro constant (created by Cannizaro), the Auger effect was discovered by Lise Meitner in 1922 and rediscovered by Pierre Auger in 1923. The effect consists in the ejection of an electron from an atom without the emission […]