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

¹ Solid State Physics Laboratory, ETH Zürich - 8093 Zürich, Switzerland
² Department of Physics and Astronomy, Ohio University Athens, OH 45701-2979, USA
³ Materials Department, University of California - Santa Barbara, CA 93106, USA

Received: 14 May 2002
Accepted: 19 December 2002

Abstract

We report electronic transport measurements on two-dimensional electron gases in a heterostructure with an embedded layer of self-assembled quantum dots. At high 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.