Theory of magneto-oscillation effects in quasi-two-dimensional semiconductor structures

A theory of magneto-oscillations of kinetic coefficients is developed for two-dimensional structures with several occupied size-quantized subbands. The Green function of a multilevel system is calculated, making allowance for intersubband scattering in moderate magnetic fields at both zero and non-zero temperatures. The temperature dependence of the Shubnikov-de Haas effect is investigated. It is shown that oscillations with frequency proportional to the concentration in the upper subband appear even if occupation of this subband is low. For the first time, the amplitude of the conductivity magneto-oscillations that are not thermally damped out is calculated. It is shown that they have frequencies proportional to the differences of the energies of size-quantization, It is predicted that there will be emergence and disappearance of beats in the magnetoconductivity at relatively small occupation of the upper subband.