Transport signatures of correlated disorder in a two-dimensional electron gas

T. Heinzel, R. D. Jaeggi, E. Ribeiro, M. v. Waldkirch, K. Ensslin, S. E. Ulloa, G. Medeiros-Ribeiro, P. M. Petroff

Published 2001-10-18Version 1

We report electronic transport measurements on two-dimensional electron gases in a Ga[Al]As heterostructure with an embedded layer of InAs self-assembled quantum dots. At high InAs dot densities, pronounced Altshuler-Aronov-Spivak magnetoresistance oscillations are observed, which indicate short-range ordering of the potential landscape formed by the charged dots and the strain fields. The presence of these oscillations coincides with the observation of a metal-insulator transition, and a maximum in the electron mobility as a function of the electron density. Within a model based on correlated disorder, we establish a relation between these effects.