Perturbative fluctuation dissipation relation for non-equilibrium finite frequency noise in quantum circuits

TL;DR

This paper derives a general perturbative method to compute finite-frequency quantum noise in non-equilibrium quantum circuits, linking noise to non-equilibrium DC current and providing explicit predictions for conductors with Ohmic environments.

Contribution

It introduces a generalized fluctuation dissipation relation for non-equilibrium quantum noise applicable to various conductors and environments.

Findings

Noise expressed through non-equilibrium DC current

Derived explicit predictions for single-channel conductors

Applicable to conductors with arbitrary Ohmic environments

Abstract

We develop a general perturbative computation of finite-frequency quantum noise which applies, in particular, to both good or weakly transmitting strongly correlated conductors coupled to a generic environment. Under a minimal set of hypotheses, we show that the noise can be expressed through the non-equilibrium DC current only, generalizing a non-equilibrium fluctuation dissipation relation. We use this relation to derive explicit predictions for the non equilibrium finite frequency noise for a single channel conductor connected to an arbitrary Ohmic environment.