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1. Mesoscopic physics: A subdiscipline of condensed-matter physics that focuses on the properties of solids in a size range intermediate between bulk matter and individual atoms or molecules. The size scale of interest is determined by the appearance of novel physical phenomena absent in bulk solids and has no rigid definition; however, the systems studied are normally in the range of 100 nanometers (the size of a typical virus) to 1000 nm (the size of a typical bacterium). Other branches of science, such as chemistry and molecular biology, also deal with objects in this size range, but mesoscopic physics has dealt primarily with artificial structures of metal or semiconducting material which have been fabricated by the techniques employed for producing microelectronic circuits. Thus mesoscopic physics has a close connection to the fields of nanofabrication and nanotechnology. Three categories of new phenomena in such systems are interference effects, quantum size effects, and charging effects. See also Artificially layered structures; Nanostructures; Quantized electronic structure (QUEST); Semiconductor heterostructures.

2. Nanostructures: A material structure assembled from a layer or cluster of atoms with size of the order of nanometers. Interest in the physics of condensed matter at size scales larger than that of atoms and smaller than that of bulk solids (mesoscopic physics) has grown rapidly since the 1970s, owing to the increasing realization that the properties of these mesoscopic atomic ensembles are different from those of conventional solids. As a consequence, interest in artificially assembling materials from nanometer-sized building blocks arose from discoveries that by controlling the sizes in the range of 1–100 nm and the assembly of such constituents it was possible to begin to alter and prescribe the properties of the assembled nanostructures.

Nanostructured materials are modulated over nanometer length scales in zero to three dimensions. They can be assembled with modulation dimensionalities of zero (atom clusters or filaments), one (multilayers), two (ultrafine-grained overlayers or coatings or buried layers), and three (nanophase materials), or with intermediate dimensionalities.

3. Quantum dot: a nanostructure that confines the motion of conduction band electrons, valence band holes, or excitons (pairs of conduction band electrons and valence band holes) in all three spatial directions. The confinement can be due to electrostatic potentials (generated by external electrodes, doping, strain, impurities), due to the presence of an interface between different semiconductor materials (e.g. in the case of self-assembled quantum dots), due to the presence of the semiconductor surface (e.g. in the case of a semiconductor nanocrystal), or due to a combination of these. A quantum dot has a discrete quantized energy spectrum. The corresponding wave functions are spatially localized within the quantum dot, but extend over many periods of the crystal lattice. A quantum dot contains a small integer number (of the order of 1-100) of conduction band electrons, valence band holes, or excitons, i.e., an integer number of elementary electric charges.

4. Shot noise: a type of electronic noise that occurs when the finite number of particles that carry energy, such as electrons in an electronic circuit or photons in an optical device, is small enough to give rise to detectable statistical fluctuations in a measurement. It is important in electronics, telecommunications and fundamental physics.

The strength of this noise increases with the average magnitude of the current or intensity of the light. Often, however, as the signal increases more rapidly as the average signal becomes stronger, shot noise often is only a problem with small currents and light intensities.

5. SPINTRONICS (SPIN elecTRONICS): Using the spin of an electron to represent binary data (0 or 1). Spintronics techniques are capable of much higher speed while requiring less power than the conventional method of using electron charges to represent data. Expected to become widely used in sensors and non-volatile memories, the first use of spintronics was in the late 1980s with the development of giant magnetoresistance (GMR) read heads for disk drives. See magnetoresistance and MRAM.

6. The spin-FET: the ferromagnetic source and drain contacts inject and collect spin-polarized electrons in the channel of a HEMT field-effect transistor. The spin precession in the channel is controlled by the gate voltage through the Rashba spin-orbit coupling. The gate voltage then controls doubly the drain current drain, by the classical field-effect and by a magnetic effect related to the electronic spin.

7. Graphene: is a single planar sheet of sp²-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. It can also be viewed as an atomic-scale chicken wire made of carbon atoms and their bonds. The carbon-carbon bond length in graphene is approximately 1.42 Å. From a physicist's point of view, graphene is the basic structural element for all other graphitic materials including graphite, carbon nanotubes and fullerenes. For a chemist, graphene is an infinitely large aromatic molecule, an extension of a family of flat polycyclic aromatic hydrocarbons called graphenes.