Electronic subbands at GaAsA [formula omitted]GaAs heterojunctions in parallel magnetic fields

Abstract

We investigated theoretically the effect of in-plane magnetic fields up to 20 T on the quasi-two dimensional (2D) electron gas confined in inversion layers of p-type GaAs at GaAsA l GaAs heterojunctions. The calculations are based on a simultaneous self-consistent solution of the Poisson and Schrödinger equations in the effective mass approximation and including exchange correlation effects. The systems were considered with different values for the 2D electron density (N S) and for the depletion charge density N dep = 5.0 × 10 10 cm −2 in the GaAs channel. The energy dispersion ϵ(k) for the in-plane direction perpendicular to the field is much affected, presenting a diamagnetic shift and a displacement of the single extremum k = 0. The respective charge density is also disturbed. A strong nonparabolicity in ϵ(k) is obtained changing drastically the effective mass of the system at the Fermi level for high magnetic fields.