THE HIGH-FREQUENCY CONDUCTIVITY TENSOR OF A 2-DIMENSIONAL ELECTRON-GAS WITH ELECTRON IMPURITY STATES IN A MAGNETIC-FIELD

The Lifshits method of local perturbations is used for studying the pr operties of a two-dimensional electron-impurity system in a quantizing magnetic field perpendicular to the plane of electron motion. The hig h-frequency conductivity tensor of the system is calculated in the mod el of independent point impurity atoms, taking into account the impuri ty states of electrons and spatial dispersion. The dissipative compone nt of the conductivity has narrow resonant peaks at frequencies of ele ctron transitions between the Landau levels and local levels, which ar e induced by the magnetic field. In zero magnetic field, these peaks m erge into one broad peak lying above the threshold frequency for elect ron transitions from a local level to the energy band. Numerical value s of the peak heights are obtained for semiconducting structures with a two-dimensional electron gas. (C) 1997 American Institute of Physics .