Fluctuation Theorem in a Quantum-Dot Aharonov-Bohm Interferometer

TL;DR

This paper explores the full counting statistics and fluctuation theorem in an interacting quantum dot Aharonov-Bohm interferometer, revealing universal relations and the role of interactions in nonlinear transport.

Contribution

It introduces a novel saddle-point solution for the cumulant-generating function that satisfies the fluctuation theorem with mean-field interactions.

Findings

Nonlinear transport coefficients obey universal relations from microscopic reversibility.

Skewness can be finite at equilibrium due to interactions.

The scattering matrix is not reversible despite the universal relations.

Abstract

In the present study, we investigate the full counting statistics in a two-terminal Aharonov-Bohm interferometer embedded with an interacting quantum dot. We introduce a novel saddle-point solution for a cumulant-generating function, which satisfies the fluctuation theorem and accounts for the interaction in the mean-field level approximation. Nonlinear transport coefficients satisfy universal relations imposed by microscopic reversibility, though the scattering matrix itself is not reversible. The skewness can be finite even in equilibrium, owing to the interaction and is proportional to the asymmetric component of nonlinear conductance.