Fluctuation relations without micro-reversibility for two-terminal conductors

TL;DR

This paper develops a non-equilibrium fluctuation-dissipation theorem for two-terminal conductors that does not rely on micro-reversibility, linking nonlinear conductance asymmetries to current fluctuation cumulants.

Contribution

It introduces a novel fluctuation-dissipation relation applicable to systems lacking micro-reversibility, expanding understanding of nonlinear transport phenomena.

Findings

Establishes a relation between antisymmetric nonlinear conductance and third cumulant of current fluctuations.

Shows the noise term is proportional to temperature, magnetic field, and voltage.

Demonstrates the theorem's applicability beyond micro-reversible systems.

Abstract

In linear transport, the fluctuation-dissipation theorem relates equilibrium current correlations to the linear conductance coefficient. Theory and experiment have shown that in small electrical conductors the non-linear I-V-characteristic of two-terminal conductor exhibits terms which are asymmetric in magnetic field and thus micro-reversibility is manifestly broken. We discuss a non-equilibrium fluctuation dissipation theorem which is not based on micro-reversibility. It connects the antisymmetric nonlinear conductance with the third cumulant of equilibrium current fluctuations and a noise term that is proportional to temperature, magnetic field and voltage.