Monte Carlo simulation of carrier number noise spectra in the integral quantum Hall regime

Abstract

The authors report Monte Carlo simulations of the spectral distribution of carrier number fluctuations due to transitions between localised and extended states in a Landau level. Surprisingly, it is found that the noise spectrum consists of a single Lorentzian, even though the density of states near the mobility edge is assumed to be continuous. The spectral features of the noise spectrum strongly resemble those observed in experiments on GaAs/AlGaAs heterostructures. They show that comparison of experiment and simulation yields an estimate of the energy separation between the mobility edges in the experimental system.