The effect of screening long-range Coulomb interactions on the metallic behavior in two-dimensional hole systems

TL;DR

This study investigates how screening long-range Coulomb interactions via a nearby ground-plane influences metallic behavior in a 2D hole system, finding minimal impact despite theoretical expectations.

Contribution

We developed a novel technique using a double quantum well heterostructure to study ground-plane effects on metallic behavior in a single sample, reducing variability.

Findings

Little change in metallic behavior with varying ground-plane distance

Ground-plane screening has minimal effect on 2DHS metallicity

Contrasts with previous insulating regime studies

Abstract

We have developed a technique utilizing a double quantum well heterostructure that allows us to study the effect of a nearby ground-plane on the metallic behavior in a GaAs two-dimensional hole system (2DHS) in a single sample and measurement cool-down, thereby maintaining a constant disorder potential. In contrast to recent measurements of the effect of ground-plane screening of the long-range Coulomb interaction in the insulating regime, we find surprisingly little effect on the metallic behavior when we change the distance between the 2DHS and the nearby ground-plane.