Modulation of Noise in Submicron GaAs/AlGaAs Hall Devices by Gating

摘要

We present a systematic characterization of fluctuations in submicron Halldevices based on GaAs/AlGaAs two-dimensional electron gas heterostructures attemperatures between 1.5 K to 60 K. A large variety of noise spectra, from 1/fto Lorentzian, are obtained by gating the Hall devices. The noise level can bereduced by up to several orders of magnitude with a moderate gate voltage of0.2 V, whereas the carrier density increases less than 60% in the same range.The significant dependence of the Hall noise spectra on temperature and gatevoltage is explained in terms of the switching processes related to impuritiesin n-AlGaAs.