Absence of localization and large dc conductance in random superlattices with correlated disorder

TL;DR

This paper investigates how structural correlations in disordered semiconductor superlattices affect dc conductance, revealing that correlated disorder can lead to extended states and high conductance peaks, thus inhibiting localization.

Contribution

It demonstrates that structural correlations in disordered superlattices create extended states, resulting in observable conductance peaks and providing a method to detect localization effects experimentally.

Findings

Presence of conductance peaks at extended state bands

Correlations inhibit localization effects

Conductance measurements reveal band structure

Abstract

We study how the influence of structural correlations in disordered systems manifests itself in experimentally measurable magnitudes, focusing on dc conductance of semiconductor superlattices with general potential profiles. We show that the existence of bands of extended states in these structures gives rise to very noticeable peaks in the finite temperature dc conductance as the chemical potential is moved through the bands or as the temperature is increased from zero. On the basis of these results we discuss how dc conductance measurements can provide information on the location and width of the bands of extended states. Our predictions can be used to demonstrate experimentally that structural correlations inhibit the localization effects of disorder.