Parabolic-quantum-well self-consistent electronic structure in a longitudinal magnetic field: Subband depopulation

We report on calculations of the fully self-consistent electronic structure of a parabolic GaAs/Alₓ{Ga}_{1{{-}}x}$As quantum well in the presence of a magnetic field in the plane of the well. We present the subband energy dispersion which depends in general on the electronic orbit center along the growth axis. We calculate the subband depopulation with increasing magnetic field for areal densities of experimental interest and compare our calculations with recent longitudinal magnetoresistance measurements. We verify the assignment of Shubnikov--de Haas oscillations to the Fermi surface passing through subband bottoms and suggest the possible existence of an oscillation not discernable in the experimental results.