Abstract: Voltage-controlled, resistance-free electric current conduction in 2-dimensional electron gases (2DEG) and its technical application at temperatures (T) up to above room temperature can be achieved by electrons with energies E<(EF-kBT) (EF=Fermi energy, k=Boltzmann constant) of a completely filled conduction band of a 2DEG which are exposed to a magnetic field Bz in the z-direction and an electric field Ey in the y-direction, which forces all of them to move in cyclotron motion in the x-y-plane with a common drift velocity vDx in the x-direction. The resulting electric drift current Jx has no resistance, as the electrons involved can neither be accelerated in a sole electric field nor disturbed by scattering from defects, impurities or phonons, as all possible final states of these processes are occupied by other electrons in the 2DEG.

Abstract: The invention relates to a process for cleaning and smoothing the surface of materials with a monocrystalline, polycrystalline or amorphous structure comprising the steps of: (a) polishing the surface to the lowest mechanically attainable roughness; (c) bombarding the surface with ions of a defined charge and kinetic energy to remove any impurities on the surface. To improve efficiency and especially to reduce the cleaning cycles it is proposed to bombard the surface with at least double-charged ions of low kinetic energy, where the potential energy of the ions causes an interaction with the bonded impurities in accordance with their high charge which removes said impurities. Furthermore the kinetic energy imparted to the ions is determined solely so that the ions can approach the atoms of the surface impurities as closely as possible without, however, penetrating the surface.

Abstract: The invention concerns a process and a device for surface-modification by physico-chemical reactions with the following steps: a) contacting a solid surface having a crystalline or amorphous structure with a reactive, gaseous fluid (gas, gas mixture, vapour or vapour mixture) which is to interact with the surface; (b) supplying activating energy to the contact area between fluid and surface by means of ions or plasmas, in order to trigger reactions between said partners. In order to improve such a process and device, the activating energy is supplied as ions having at least a double charge and low kinetic energy or plasma streams with a sufficient proportion of ions having at least a double charge and low kinetic energy. The kinetic energy imparted to the ions is selected so that it allows the ions to closely approach the surface atoms but no to enter the surface.