The Quantum Theory of Conductivity of Spatially - Heterogeneous Systems

Abstract

The quantum theory of conductivity of semiconductor objects, to which the quantum wells, wires and dots concern, is constructed. Average values of current and charge densities, induced by a weak electromagnetic field, are calculated. It is shown, that in both cases average current and charge densities contain two contributions, first of which is expressed through electric field, and second - through a spatial derivative of electric field. Appropriate expressions for the conductivity tensor, dependent on coordinates and applicable to any spatially-heterogeneous systems, are deduced. The results may be used in the theory of secondary light radiation from low-dimensional objects in cases of monochromatic light and light pulses.