Electron-electron interactions in a weakly screened two-dimensional electron system

TL;DR

This study investigates electron-electron interactions in a two-dimensional electron system on liquid helium, revealing a transition from independent-electron behavior to strong interactions as electron density varies.

Contribution

It provides new experimental data on electron interactions at much lower densities than previously studied, covering both weakly and strongly interacting regimes.

Findings

Observation of a crossover from SCBA to Drude theory with changing electron density

Extension of electron density range by two orders of magnitude

Identification of regimes of electron-electron interaction strength

Abstract

We probe the strength of electron-electron interactions using magnetoconductivity measurements of two-dimensional non-degenerate electrons on liquid helium at 1.22 K. Our data extend to electron densities that are two orders of magnitude smaller than previously reported. We span both the independent-electron regime where the data are qualitatively described by the self-consistent Born approximation (SCBA), and the strongly-interacting electron regime. At finite fields we observe a crossover from SCBA to Drude theory as a function of electron density.