Among the astonishing properties of graphene, a high mobility of the charge carriers has placed this material into the focus of intensive research efforts, aimed at developing high-speed graphene-based electronic devices. The first device of this family, a graphene field-effect transistor (GFET), still remains a promising candidate for applications in flexible electronic circuits. An essential […]
A chemical compound or molecule consisting of two identical simpler molecules is a dimer. If one of the simpler molecules is excited while the other is in its ground, non-excited, state we talk about excimers. They are excited dimers which are non-bonding in the ground state. Thus, excimers can be considered evanescent quasi-particles that typically […]
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 backplate of the instrument is covered with flour or sand, and bowed until it reached resonance […]
Chemistry • Condensed matter • Materials • Physics • Quantum physics
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 gap (graphene is gapless). However, an exhaustive experimental search has been inconclusive, resulting in doubts […]
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 interface with semiconductor or superconductor materials. Now a team of researchers from DIPC and some […]
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 on a different approach , this postulate is still valid. Atoms can acquire internal energy, that […]
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 energies that an atom can have? A famous experiment in 1914, by the German physicists […]
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 molecular orbital (HOMO− LUMO) gap. These features result in an unusual stability and chemical inertness […]
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 so far to test this interpretation has confirmed these results. Yet many scientists still find […]
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. Its foundations were developed very rapidly during the next few years, primarily by Born, Heisenberg […]