Steady state work fluctuations of a dragged particle under external and thermal noise

TL;DR

This paper analyzes the work fluctuations of a particle in a moving harmonic trap under external Poissonian shot noise and Gaussian noise, deriving exact large deviation forms and showing violation of the fluctuation theorem.

Contribution

It provides exact expressions for work distribution in a nonequilibrium steady state with Poissonian and Gaussian noise, revealing fluctuation theorem violations.

Findings

Large deviation forms of work distribution derived

Fluctuation theorem is violated in the model

Negative work fluctuations can be more probable than positive ones

Abstract

We consider a particle, confined to a moving harmonic potential, under the influence of friction and external asymmetric Poissonian shot noise (PSN). We study the fluctuations of the work done to maintain this system in a nonequilibrium steady state. PSN generalizes the usual Gaussian noise and can be considered to be a paradigm of external noise, where fluctuation and dissipation originate from physically independent mechanisms. We consider two scenarios: (i) the noise is given purely by PSN and (ii) in addition to PSN the particle is subject to white Gaussian noise. In both cases we derive exact expressions for the large deviation form of the work distribution, which are characterized by the time scales of the system. We show that the usual steady state fluctuation theorem is violated in our model and that in a certain parameter regime large negative work fluctuations are more likely to occur than the corresponding positive ones, though the average work is always positive.