Landau-Level Broadening in GaAs/AlGaAs Heterojunctions

Abstract

The broadening of Landau levels is calculated in a two-dimensional electron system at a GaAs/AlGaAs heterostructure in strong magnetic fields. Scatterers are assumed to be charged ions in the AlGaAs layer and in the bulk GaAs layer. The self-consistent determination of the broadening and screening is shown to be essential and gives rise to a drastic reduction of the broadening when the spacer thickness is sufficiently large. The broadening of cyclotron resonance and the peak values of the diagonal conductivity are also calculated.