Electron-Assisted Hopping in Two Dimensions

TL;DR

This paper investigates how electron-electron interactions, rather than phonons, facilitate hopping conductivity in two-dimensional systems transitioning from weak to strong localization, especially when electrons are out of equilibrium with phonons.

Contribution

It demonstrates that in systems with large localization length, hopping transport is primarily assisted by electron-electron interactions instead of phonons.

Findings

Hopping conductivity depends solely on electron temperature when electrons are out of equilibrium.

Electron-electron interactions dominate hopping transport in large localization length regimes.

Non-ohmic effects reveal the crossover from weak to strong localization.

Abstract

We have studied the non-ohmic effects in the conductivity of a two-dimensional system which undergoes the crossover from weak to strong localization with decreasing electron concentration. When the electrons are removed from equilibrium with phonons, the hopping conductivity depends only on the electron temperature. This indicates that the hopping transport in a system with a large localization length is assisted by electron-electron interactions rather than by the phonons.