Local transport in a disorder-stabilized correlated insulating phase

TL;DR

This paper reports the experimental observation of a disorder-stabilized correlated insulating phase in 2D heterostructures, characterized by universal hopping transport and a pinned electron solid ground state, independent of disorder topology.

Contribution

It demonstrates the realization of a correlated insulator at low electron densities in 2D heterostructures with a universal transport mechanism influenced by disorder and Coulomb interactions.

Findings

Insulating phase observed at low electron densities.

Transport characterized by universal hopping mechanism.

Insulating state stabilized by disorder and Coulomb interactions.

Abstract

We report the experimental realization of a correlated insulating phase in 2D GaAs/AlGaAs heterostructures at low electron densities in a limited window of background disorder. This has been achieved at mesoscopic length scales, where the insulating phase is characterized by a universal hopping transport mechanism. Transport in this regime is determined only by the average electron separation, independent of the topology of background disorder. We have discussed this observation in terms of a pinned electron solid ground state, stabilized by mutual interplay of disorder and Coulomb interaction.