Charge Transport in the Dense Two-Dimensional Coulomb Gas

TL;DR

This paper investigates charge transport in a dense 2D Coulomb gas, proposing a collective partner transfer mechanism at high densities that explains experimental deviations from standard free particle drift theory.

Contribution

It introduces a new collective partner transfer mechanism for charge transport in dense 2D Coulomb gases, extending understanding beyond the traditional free particle drift model.

Findings

Standard free particle drift applies only at low densities.

Collective partner transfer explains experimental deviations.

Dynamical scaling arises from the new mechanism.

Abstract

The dynamics of a globally neutral system of diffusing Coulomb charges in two dimensions, driven by an applied electric field, is studied in a wide temperature range around the Berezinskii-Kosterlitz-Thouless transition. I argue that the commonly accepted ``free particle drift'' mechanism of charge transport in this system is limited to relatively low particle densities. For higher densities, I propose a modified picture involving collective ``partner transfer'' between bound pairs. The new picture provides a natural explanation for recent experimental and numerical findings which deviate from standard theory. It also clarifies the origin of dynamical scaling in this context.