Interactions in high-mobility 2D electron and hole systems

TL;DR

This paper investigates how electron-electron interactions influence conductivity in high-mobility 2D electron and hole systems across intermediate and ballistic regimes, highlighting the role of fluctuation potential range.

Contribution

It provides experimental analysis of interaction corrections in high-mobility 2D systems within the ballistic regime, emphasizing the impact of fluctuation potential character.

Findings

Interaction correction observed in resistance and magnetoresistance.

Short-range and long-range fluctuation potentials affect interaction manifestations.

Results align with recent ballistic regime interaction theories.

Abstract

Electron-electron interactions mediated by impurities are studied in several high-mobility two-dimensional (electron and hole) systems where the parameter $k_BT\tau /\hbar $ changes from 0.1 to 10 ($\tau$ is the momentum relaxation time). This range corresponds to the \textit{intermediate} and \textit {ballistic} regimes where only a few impurities are involved in electron-electron interactions. The interaction correction to the Drude conductivity is detected in the temperature dependence of the resistance and in the magnetoresistance in parallel and perpendicular magnetic fields. The effects are analysed in terms of the recent theories of electron interactions developed for the ballistic regime. It is shown that the character of the fluctuation potential (short-range or long-range) is an important factor in the manifestation of electron-electron interactions in high-mobility 2D systems.