Category archives: Condensed matter

The wave nature of light expresses itself in the propagation all over space, showing an intrinsic limitation to be localized beyond the so-called diffraction limit which is of the order of half the wavelength of the photons propagating. However when interacting with matter, light often gets reflected, diffracted, scattered or absorbed depending on the interactions […]

Since the discovery that graphene, the two dimensional carbon allotrope, can be isolated and incorporated into electronic devices intense research efforts have been triggered. Driving forces usually mentioned behind the experimental and theoretical studies of graphene are the exceptional electronic properties, in particular the high electron mobilities, the long spin coherence lengths and the possibility […]

The electronic wave function of an n-electron molecule depends on 3n spatial and n spin coordinates. In a sense, the wave function of a many-electron molecule contains more information than is needed and is lacking in direct physical significance. This has prompted the search for methods that involve fewer variables than the wave function and […]

Topological insulators are materials with special universal properties, which are protected against perturbations. Such properties are theoretically described by topology, a branch of mathematics concerned with the properties of geometrical objects that are unchanged by continuous deformations. Concretely, topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have […]

A class of materials of utmost fundamental and applied interest is that of semicrystalline polymers. Actually, all solid synthetic polymers are, in general, partly crystalline and partly amorphous. The degree of crystallinity depends on the polymer structure and on how the solid is prepared. Rapid cooling of the molten polymer favors formation of an amorphous […]

The scattering of conduction electrons in metals owing to impurities with magnetic moments is known as the Kondo effect, after Jun Kondo, who analysed the phenomenon in 1964. This scattering increases the electrical resistance and has the consequence that, in contrast to ordinary metals, the resistance reaches a minimum as the temperature is lowered and […]

Metal complexes are typically regarded as catalysts that convert organic substrates into more valuable compounds; however, to date, catalytic transformations of metal complexes are practically unknown and represent a complete new way of thinking in catalysis. Their development can expand the scope of bioorthogonal chemical reactions to inorganic substances and metal-based prodrugs, fostering the creation […]

Imagine a bucket filled with hard spheres. As these spheres are free to pack together as closely as geometry allows they tend to adopt a close-packed structure, a structure in which there is least unfilled space. X-ray diffraction studies reveal that many metallic elements have close-packed structures. This simple fact explains a couple of very […]

In ‘Chemistry Essentials for Dummies‘, John T. Moore writes: Matter is anything that has mass and occupies space. It can exist in one of three classic states: solid, liquid, and gas. When a substance goes from one state of matter to another, the process is called a change of state, or phase change. As he […]

We usually think of crystals as composed of different atoms in certain proportions, this proportion being the molecular fórmula that represents the crystal. However, it is not surprising that any molecule could be the basis of a crystal structure, whether a simple molecule such as methane, or a complicated molecule such as a protein or […]