Gaussian white noise as a resource for microscopic engines

TL;DR

This paper demonstrates that Gaussian white noise, traditionally linked to equilibrium, can be harnessed as a resource to drive microscopic engines out of equilibrium and generate work, especially in asymmetric potentials.

Contribution

It introduces a model where Gaussian white noise drives a system into a non-equilibrium steady state, enabling work extraction from an equilibrium bath.

Findings

Gaussian white noise can induce a non-equilibrium current in asymmetric potentials.

Explicit calculation of current in three different limits.

Derived an expression for the efficiency of noise-driven microscopic engines.

Abstract

We show that uncorrelated Gaussian noise, despite its paradigmatic association with thermal equilibrium, can drive a system out of equilibrium and can serve as a resource from which work can be extracted. We consider an overdamped particle in a periodic potential with an internal degree of freedom and a state-dependent friction, coupled to an equilibrium bath. Applying additional Gaussian white noise drives the system into a non-equilibrium steady state and causes a finite current if the potential is spatially asymmetric. We calculate the current explicitly in the three complementary limits. Since the particle current is driven solely by additive Gaussian white noise, this shows that the latter can potentially be exploited as a work resource to power small engines. By comparing the extracted power to the energy injection due to the noise, we find an expression for the efficiency of such an engine.