Subband Structure of an Accumulation Layer under Strong Magnetic Fields

Abstract

The electronic structure of subbands in an n-channel accumulation layer on a Si (100) surface is studied in the Hartree self-consistent approximation. An image potential arising form the existence of an interface between the semiconductor and its oxide is taken into account. It reduces subband-splittings especially at high concentrations of surface electrons. Effects of strong magnetic fields applied parallel to the surface are investigated. The electronic structure becomes a mixture of the electric subbands and the magnetic fields applied parallel to the surface are investigated. The electronic structure becomes a mixture of the electric subbands and the magnetic surface states. Optical spectra due to intersubband transitions are calculated. The absolute value of the theoretical peak energy is much smaller than the experiment of Kamgar et al., but its shift caused by magnetic fields is in reasonable agreement with their experiment.