Magnetotransport and electron states in two-dimensional systems including the effect of a random potential and the boundary conditions

Abstract

The existence of the plateaus in the Hall conductivity of a disordered 2D system as a function of the filling factor is related to the existence of localized (“bulk”) states which “pin” the Fermi level, and to states, which are due to the boundary of the system. The properties of the latter states are investigated by studying a disordered system of finite width subject to boundary conditions ranging from “Dirichlet's” to “periodic”. The results suggest that the boundary states are extended, and merge into the centres of the magnetic subband, when “switching on” the periodic boundary conditions.