Resonant tunneling and hopping through a series of localized states in a two-dimensional electron gas

Abstract

We report measurements of the temperature and length dependence of the conductance of a wide two-dimensional electron gas in a strongly localized regime. Our results indicate that the conduction occurs via resonant tunneling below about 0.1 K and, at higher temperatures, via hopping through channels that contain more than one localized state. A dramatic increase of the average logarithm of conductance with the increasing sample length is observed in the tunneling regime, for which there is no satisfactory theoretical explanation yet. This effect persists even up to 4.2 K. © 1991 The American Physical Society.