MAGNETIC-FIELD DEPENDENCE OF THE ELECTRONIC CHARGE-DENSITY, CYCLOTRONMASS, AND FERMI ENERGY IN A GAAS-GA1-XALXAS HETEROJUNCTION

A theoretical study of the magnetic-field dependence of the two-dimens ional electron-gas density, cyclotron mass, and Fermi energy in a modu lation-doped GaAs-Ga1-xAlxAs heterojunction under a magnetic field app lied perpendicular to the interface is presented. The study, based on both the envelope-function approximation and a parametric self-consist ent approach, takes into account band-nonparabolicity effects. Numeric al results show that the above-mentioned quantities as well as a scree ning parameter introduced in the calculations are oscillatory function s of the magnetic field. Our results are in good agreement with experi mental data previously reported and show that nonparabolicity may sign ificantly influence the behavior of the cyclotron-resonance parameters . (C) 1996 American Institute of Physics.