Specialisation has necessarily led to the fragmentation of knowledge, creating loosely connected disciplines in which discoveries in one area are hardly known in others. This implies that the flow of knowledge is severely restricted among disciplines or even among different areas within the same discipline. In recent decades, different approaches have been proposed to overcome […]
Tetrapyrroles,“the pigments of life”,are key molecules for the metabolism of living organisms, supporting functions of vital importance such as electron transport, light-harvesting and oxygen reduction. Within this family of compounds, porphyrins are organic pigments characterized by the possesion of a cyclic group of four linked nitrogen-containing rings called porphyrin, the nitrogen atoms of which are […]
It is very difficult to obtain exact solutions to systems involving interactions between more than two bodies, using either classical mechanics or quantum mechanics. To understand the physics of many-body systems, it is necessary to make use of approximation techniques or model systems that capture the essential physics of the problem. T he complexity of […]
A nanoantenna with balanced electric and magnetic dipole moments exhibits a directive radiation pattern with zero backscattering. This is known as the first Kerker condition after Kerker, Wang, and Giles, who predicted in 1983 that, under plane wave illumination, magnetic spheres with equal relative permittivity and permeability radiate no light in the backscattering direction. They […]
The common understanding of the uncertainty relation says that it is impossible to measure both the position and the momentum of a subatomic particle, in the same instant to unlimited accuracy. The more accurate is the measurement of the momentum, the less accurate is the measurement of the position in that instant, and vice versa […]
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 random and have no long-range ordered pattern. These kind of […]
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 […]
Quantum objects are not abstract entities. On the contrary, they are quite real, As such, individual quantum objects can be detected, manipulated and their characteristics analysed using the appropriate techniques. Take the case of a single molecule adsorbed on a substrate. Scanning Tunneling Microscopy (STM) would reveal electron densities of molecular orbitals, could be used […]
Terahertz (THz) radiation is all around us. For example, this page emits blackbody radiation mainly in the THz region (broadly from 0.3 THz to 30 THz). Because terahertz radiation begins at a wavelength of around one millimeter and proceeds into shorter wavelengths, it is sometimes known as the submillimeter band, and its radiation as submillimeter […]
Two-dimensional (2D) materials are extraordinary for two main reasons. One is the set of mechanical properties that makes those materials a versatile playground where multiple modelling objects are possible, from the thinnest membranes with minuscule bending rigidity to very stiff plates, all with very reproducible parameters. The other reason is that both the electronic and […]