Magnetophonon effect in the energy relaxation rate of electrons in a GaAs heterostructure

Abstract

The magnetophonon effect in the energy relaxation rate for a two-dimensional electron gas (2D EG) is investigated within an electron-temperature model. The relative contribution of the acoustic phonons and LO phonons is analyzed. The behavior of the contribution of acoustic phonons is studied as a function of the effective thickness of the 2D EG. A lower limit on the thickness of the 2D EG is found, below which the continuum Debye model for acoustic phonons is no longer valid. Experimental conditions are determined for the observation of the magnetophonon effect in the energy relaxation rate for a low-density electron gas. The effect of the screening of the electron-phonon interaction on the energy relaxation rate is investigated within the random-phase approximation. We find that all the temperature dependence of the energy relaxation rate is contained in the phonon occupation numbers and that the magnetophonon peak positions are shifted to lower magnetic fields with increasing electron-sheet density.