Tunneling Density of States of the Interacting Two-Dimensional Electron Gas

TL;DR

This paper studies how electron-electron interactions affect the density of states in a ballistic two-dimensional electron gas, revealing a suppression at the Fermi level that varies with electron density and gate presence.

Contribution

It provides a nonperturbative analysis of the density of states in 2D electron gases using path integral techniques, especially near the Fermi surface.

Findings

Density of states is suppressed at the Fermi level to a finite value.

Suppression increases as electron density decreases.

Presence of gates weakens the suppression.

Abstract

We investigate the influence of electron--electron interactions on the density of states of a ballistic two--dimensional electron gas. The density of states is determined nonperturbatively by means of path integral techniques allowing for reliable results near the Fermi surface, where perturbation theory breaks down. We find that the density of states is suppressed at the Fermi level to a finite value. This suppression factor grows with decreasing electron density and is weakened by the presence of gates.