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 […]
Real life is sometimes very different from laboratory settings. Take superconductivity, for example. In order to reach, it you either need extremely low temperatures, extremely high pressures or a combination of both; something that makes very difficult to conceive an everyday application out of a laboratory. Something similar happens with other new materials, but in […]
Euclid is an ESA mission to map the geometry of the Universe and better understand the mysterious dark matter and dark energy, which make up most of the energy budget of the cosmos. The mission will investigate the distance-redshift relationship and the evolution of cosmic structures by measuring shapes and redshifts of galaxies and clusters […]
A silicate is any of a group of substances containing negative ions composed of silicon and oxygen. With this definition it is no surprise that silicates are a huge group. Natural silicates form the mayor component of most rocks, the bulk (90 %) of the Earth´s outer crust and one third of all minerals. The […]
The standard explanation of superconductivity goes more or less like this. Electrical resistance is due to collisions of the electrons (whether treated as particles or waves) with impurities, imperfections, and especially the lattice vibrations of the metal crystal. The lattice vibrations of the solid will decrease as the temperature falls, because the entropy, which represents […]
The absence of mirror symmetry, or chirality, is behind striking natural phenomena found in systems as diverse as DNA and crystalline solids. A remarkable example occurs when chiral semimetals with topologically protected band degeneracies are illuminated with circularly polarized light. In circularly polarized light, the tip of the electric vector describes a circular helix about […]
Transition metal dichalcogenides (TMDs) are layered compounds which can be thinned down to the single-layer limit. While mechanical exfoliation generates atomically thin TMD flakes possessing an area of a few square microns, chemical and physical methods provide high-quality monolayers on large-area substrates, which are suitable for actual technological applications. Similar to other two-dimensional materials, TMD […]