Mesoscopic Coulomb drag, broken detailed balance and fluctuation relations

TL;DR

This paper investigates the Coulomb drag effect in a double quantum dot system, demonstrating that nonlinear fluctuation relations hold even when detailed balance is broken far from equilibrium.

Contribution

It provides the first theoretical proposal to verify nonlinear fluctuation relations in a Coulomb drag system without detailed balance.

Findings

Fluctuation relations are satisfied despite broken detailed balance.

Proposes an experimental setup with double quantum dots.

Confirms theoretical predictions about nonequilibrium fluctuation relations.

Abstract

When a biased conductor is put in proximity with an unbiased conductor a drag current can be induced in the absence of detailed balance. This is known as the Coulomb drag effect. However, even in this situation far away from equilibrium where detailed balance is explicitly broken, theory predicts that fluctuation relations are satisfied. This surprising effect has, to date, not been confirmed experimentally. Here we propose a system consisting of a capacitively coupled double quantum dot where the nonlinear fluctuation relations are verified in the absence of detailed balance.