Quasi-Ballistic Electron Transport in Random Superlattices

TL;DR

This paper demonstrates that introducing specific short-range correlations in disordered semiconductor superlattices can significantly enhance electron conductance, leading to quasi-ballistic transport and reducing localization effects.

Contribution

It provides a theoretical framework showing how structural correlations in disordered superlattices can promote quasi-ballistic electron transport, a novel approach to controlling disorder effects.

Findings

Correlated disorder enhances dc conductance

Structural correlations inhibit localization effects

Predictions for experimental superlattice design

Abstract

We theoretically study electron transport in disordered, quantum-well based, semiconductor superlattices with structural short-range correlations. Our system consists of equal width square barriers and quantum wells with two different thicknesses. The two kinds of quantum wells are randomly distributed along the growth direction. Structural correlations are introduced by adding the constraint that one of the wells always appears in pairs. We show that such correlated disordered superlattices exhibit a strong enhancement of their dc conductance as compared to usual random ones, giving rise to quasi-ballistic electron transport. Our predictions can be used to demonstrate experimentally that structural correlations inhibit the localization effects of disorder. We specifically describe the way superlattices should be built and experiments should be carried out for that purpose.