Category Archives: Condensed matter

Luthiers still use Chladni figures in the design and construction of acoustic instruments such as violins, guitars, and cellos. The technique invented by the German physicist and musician Ernst Chladni (1756–1827) shows the modes of vibration under forcing. The […]

Graphene is a two-dimensional allotrope of carbon made of hexagons. In February 2015, penta-graphene, only made of pentagons, was theoretically proposed as another two-dimensional allotrope of carbon . Apparently, it is dynamically, thermally, and mechanically stable, exhibiting a large band […]

In order to study new solid state magnetic properties appropiate new laboratory models are needed. In particular, there is a necessity for a substrate to investigate new forms of magnetic coupling with nanoscale ferromagnets and the exotic physics at the […]

An atom in an excited state gives off energy by emitting a photon, a quantum of electromagnetic radiation, according to Bohr’s second postulate. Although Bohr’s specific model of the atom has been vastly extended and incorporated into models based […]

The success of Bohr’s model of the atom in accounting for the spectrum of hydrogen left this question: Could experiments show directly that atoms do have only certain, separate energy states? In other words, are there really gaps between the […]

Al13− is one of the most attractive of the so-called magic clusters. It has a perfect icosahedral symmetry with an aluminum atom at the center, a closed-shell electronic configuration (40 electrons), and a large highest occupied molecular orbital−lowest unoccupied […]

The idea that the solution of Schrödinger’s equation is a wave that represents, not a physical wave, but the probability of finding the associated particle in some specific condition of motion has had great success. In fact, every experiment devised […]

By the mid-1920s it was clear that “things” (electrons, atoms, molecules) long regarded as particles also show wave properties. This fact is the basis for the currently accepted theory of atomic structure. This theory, quantum mechanics, was introduced in 1925. […]

Silicon surfaces of crystalline solids are part of conventional electronics, but their exploitation in novel materials combining two-dimensional electron states (2DESs) and magnetism, which play an important role in the development of next-generation electronics, still remains elusive. The appearance of […]

Amplifying Voltage. If we place a large resistor in a circuit containing a transistor we can amplify the incoming voltage, since according to Ohm’s law voltage is equal to current times resistance. So a current crossing a small resistance corresponds […]