Probing the coexistence of semiclassical transport and localization in a two-dimensional electron gas using microwave radiation

Abstract

We have performed magnetoresistance measurements on a GaAs/AlGaAs two-dimensional electron gas under microwave heating. Both the magneto-oscillations and magnetoresistance minima are used as electron thermometers to determine the electron effective temperature T-e. When there is no clear cyclotron gap, it is found that T-e determined from these two methods can be substantially different such that we can still distinguish localized electrons from the semiclassical conducting ones. The almost constant T-e obtained from the magnetoresistance minima reveals the survived equivalence between different Landau-band tails under insufficient localization. (C) 2012 Elsevier Ltd. All rights reserved.