Ground-plane screening of Coulomb interactions in two-dimensional systems: How effectively can one two-dimensional system screen interactions in another?

TL;DR

This paper investigates how effectively a two-dimensional system can screen Coulomb interactions in another 2D system, revealing that a 2D layer can be as effective as a metal, with intralayer screening reducing ground-plane effects in the metallic regime.

Contribution

It provides a theoretical analysis demonstrating that a 2D system can effectively screen Coulomb interactions, comparable to a metal, and explains the reduced screening observed in metallic states.

Findings

A 2D system can screen Coulomb interactions as effectively as a metal.

Intralayer screening diminishes the ground-plane's effect in metallic regimes.

The study clarifies the role of intralayer screening in 2D systems.

Abstract

The use of a nearby metallic ground-plane to limit the range of the Coulomb interactions between carriers is a useful approach in studying the physics of two-dimensional (2D) systems. This approach has been used to study Wigner crystallization of electrons on the surface of liquid helium, and most recently, the insulating and metallic states of semiconductor-based two-dimensional systems. In this paper, we perform calculations of the screening effect of one 2D system on another and show that a 2D system is at least as effective as a metal in screening Coulomb interactions. We also show that the recent observation of the reduced effect of the ground-plane when the 2D system is in the metallic regime is due to intralayer screening.