Theory of self-consistency effects in the electronic structure of inversion layers in a perpendicular magnetic field

Abstract

Recently a new kind of magnetic-field-dependent self-consistent calculation was developed for quantum wells and for inversion layers with two or more populated subbands in a perpendicular magnetic field. Numerical results show for inversion layers in bicrystals that qualitatively new features of the Landau level spectrum, of the inversion electron density, and of the subband occupation occur. It is shown here in an almost analytical way qualitatively why these new structures occur in inversion layers in systems like bicrystals, δ-doping layers, and MIS-structures. This is achieved by analyzing the dependence of the band bending and of the subband energies on the magnetic-field-dependent occupation of the Landau levels according to their ordering and to their degeneration. Analytical estimates are given which yield results in good agreement with the numerical ones. Most important is the behaviour of the spectrum where Landau levels coming from different subbands are crossing each other.