On the Electron-Electron Interactions in Two Dimensions

TL;DR

This paper reviews experiments on electron-electron interactions in 2D systems, showing consistent renormalization effects across different materials and emphasizing the importance of data interpretation methods.

Contribution

It provides a comprehensive analysis of experimental data, clarifies the influence of various parameters, and discusses the complexity of interactions in 2D electron and hole systems.

Findings

Renormalization of spin susceptibility, effective mass, and g*-factor is consistent across different 2D systems.

Discrepancies mainly arise from different data interpretation methods, not material properties.

Electron-electron interactions in 2D holes may be more complex than in electrons.

Abstract

In this paper, we analyze several experiments that address the effects of electron-electron interactions in 2D electron (hole) systems in the regime of low carrier density. The interaction effects result in renormalization of the effective spin susceptibility, effective mass, and g*-factor. We found a good agreement among the data obtained for different 2D electron systems by several experimental teams using different measuring techniques. We conclude that the renormalization is not strongly affected by the material or sample-dependent parameters such as the potential well width, disorder (the carrier mobility), and the bare (band) mass. We demonstrate that the apparent disagreement between the reported results on various 2D electron systems originates mainly from different interpretations of similar "raw" data. Several important issues should be taken into account in the data processing, among them the dependences of the effective mass and spin susceptibility on the in-plane field, and the temperature dependence of the Dingle temperature. The remaining disagreement between the data for various 2D electron systems, on one hand, and the 2D hole system in GaAs, on the other hand, may indicate more complex character of electron-electron interactions in the latter system.