Impurity-screening effects on electronic states of the two-dimensional system under a quantizing magnetic field.

Abstract

Single-particle energy levels and wave functions for a two-dimensional electron system, confined to an annular film (the Corbino geometry) in the presence of a perpendicular magnetic field are exactly determined in the symmetric gauge. For the ideal system, free of impurities, the problem is shown to be exactly solved. The behavior of the electronic states in some models of impurity potentials is examined. The influence of the impurity screening on the eigenstates for the case of semiconductor inversion layers is analyzed. It is shown that the screening effects are quite important because screening will be reduced in the presence of magnetic fields. Landau levels are determined as a function of several parameters, namely, the strength of interaction, the screening length, and the distance of the electron from impurity. Wave functions, radial densities, and matrix elements are calculated.