Fluctuation theorem for a double quantum dot coupled to a point-contact electrometer

TL;DR

This paper derives the full counting statistics and fluctuation theorem for a double quantum dot system monitored by a quantum point-contact electrometer, revealing universal relations between current and noise.

Contribution

It introduces a master equation approach with counting fields for the coupled DQD-QPC system and derives universal fluctuation relations.

Findings

Full counting statistics consistent with fluctuation theorem

Universal relations between non-linear current and noise

Master equation with generalized local detailed-balance

Abstract

We study single-electron transport through a double quantum dot (DQD) monitored by a capacitively coupled quantum point-contact (QPC) electrometer. We derive the full counting statistics for the coupled DQD - QPC system and obtain the joint probability distribution of the charges transferred through the DQD and the QPC consistent with the fluctuation theorem (FT). The system can be described by a master equation with tunneling rates depending of the counting fields and satisfying a generalized local detailed-balance relation. Furthermore, we derive universal relations between the non-linear corrections to the current and noise, which can be verified in experiment.