The magnitude of many of the exotic phenomena predicted for topological semimetals is directly proportional to something called the Chern number. Given the importance of the Chern number magnitude for these phenomena, it is just natural to wonder whether there is an upper limit for it and whether there are real materials in which this […]
A new fluorescent bicolour indicator, an organic molecule, could help detect the daughter atom of a neutrinoless double beta decay. If this is achieved, there would be an explanation to the matter-anti matter asymmetry in the universe. Experiments performed in 1909 by Geiger and Marsden, also called Rutherford gold foil experiment because Rutherford was their […]
Until 1932, atoms were considered to consist in positive charges, called protons, located within the atomic nucleus, where the majority of the mass of the atom is concentrated, and negative charges, identified as electrons, surrounding the nucleus to make it electrically neutral. However, in 1932 James Chadwick discovered the neutron, an uncharged particle located at […]
When we consider the variety of possible wonder applications of plasmonic nanoparticles we usually forget a key aspect: how these laboratory results can be transformed into something really usable in everyday life. For that to occur some not-that-simple problems must be resolved first. For example, plasmonic nanoparticles exhibit excellent light-harvesting properties in the visible spectral […]
Graphene is a diamagnetic material, this is, unable of becoming magnetic. However, a triangular piece of graphene is predicted to be magnetic. This apparent contradiction is a consequence of “magic” shapes in the structure of graphene flakes, which force electrons to “spin” more easily in one direction. Triangulene is a triangular graphene flake, which possesses […]
Condensed matter • Materials • Nanotechnology • Quantum physics • Theoretical physics
When two photons with the same energy interact with a nonlinear material, they “combine” and generate a new photon with twice the energy of the initial photons. More precisely, two photons at the fundamental frequency are absorbed by a plasmonic structure to emit one photon at the second-harmonic frequency. This is called second-harmonic generation. Second-harmonic […]
We all know what glass is, don’t we? We just point to the nearest window and it is that transparent sheet. Humans have been producing glass for at least 6,000 years, way before they knew how to smelt iron. Actually, the chemistry is well known: to produce window glass we just heat a mixture of […]
Graphene nanoribbons (GNRs), are strips of graphene with ultra-thin width (<50 nm). Graphene ribbons, introduced as a theoretical model by Mitsutaka Fujita and coauthors to examine the edge and nanoscale size effect in graphene, have emerged as a promising material for nanoelectronics, as they combine many of the extraordinary properties of graphene with a high […]
In the quantum theory of many-body systems, collective oscillations are called collective excitations. In a quantum context, everything is quantized. Hence, collective excitations become quantized modes because of the cooperative motion of the whole system as a result of interactions between particles. They may be electronic excitations in atoms and are referred excitons. In most […]
Superconductivity is a physical phenomenon in which some materials exhibit zero electrical resistance when cooled down below a certain critical temperature. As surprising as it can be, the critical temperature of these materials can be modified by reducing the sample size to about a million times the size of the objects we are used to […]
