Electron-electron interaction at decreasing $k_Fl$

TL;DR

This study investigates how electron-electron interactions influence conductivity in heterostructures as the disorder increases, showing the diffusion theory's applicability down to specific conditions and the diminishing role of interactions with increased disorder.

Contribution

It provides a detailed analysis of electron-electron interactions' contribution to conductivity at low $k_F l$, extending the understanding of diffusion theory's limits in disordered systems.

Findings

Diffusion theory valid down to $k_F l oughly 1.5-2$

Electron-electron interactions contribute less to conductivity than interference effects

Role of electron-electron interactions decreases rapidly as $k_F l$ decreases

Abstract

The contribution of the electron-electron interaction to conductivity is analyzed step by step in gated GaAs/InGaAs/GaAs heterostructures with different starting disorder. We demonstrate that the diffusion theory works down to $k_F l\simeq 1.5-2$, where $k_F$ is the Fermi quasimomentum, $l$ is the mean free paths. It is shown that the e-e interaction gives smaller contribution to the conductivity than the interference independent of the starting disorder and its role rapidly decreases with $k_Fl$ decrease.