Theory of acoustic-phonon assisted magnetotransport in 2D electron systems at large filling factors

A microscopic theory of the phonon-induced resistance oscillations in weak perpendicular magnetic fields is presented. The calculations are based on the consideration of interaction of two-dimensional electrons with three-dimensional (bulk) acoustic phonons and take into account anisotropy of the phonon spectrum in cubic crystals. The magnetoresistance is calculated for [001]-grown GaAs quantum wells. The results are in agreement with available experimental data. Apart from the numerical results, analytical expressions for the oscillating part of magnetoresistance are obtained. These expressions are valid in the region of high-order magnetophonon resonances and describe the oscillating magnetoresistance determined by several groups of phonons polarized along certain high-symmetry directions.