Work fluctuations in a nonlinear micromechanical oscillator driven far from thermal equilibrium

TL;DR

This study investigates work fluctuations in a nonlinear micromechanical oscillator driven far from equilibrium, revealing behaviors like state coexistence, transition-induced variance peaks, and exponential fluctuation dependence, challenging traditional fluctuation theorems.

Contribution

It demonstrates how nonlinear dynamics and bistability affect work fluctuations, extending fluctuation theorem understanding to far-from-equilibrium micromechanical systems.

Findings

Work variance peaks at equal occupation of bistable states.

Work fluctuations depend exponentially on inverse noise intensity.

Nonlinear response shows deviations from conventional fluctuation theorems.

Abstract

We explore fluctuation relations in a periodically driven micromechanical torsional oscillator. In the linear regime where the modulation is weak, we verify that the ratio of the work variance to the mean work is constant, consistent with conventional fluctuation theorems. We then increase the amplitude of the periodic drive so that the response becomes nonlinear and two nonequilibrium oscillation states coexist. Due to interstate transitions, the work variance exhibits a peak at the driving frequency at which the occupation of the two states is equal. Moreover, the work fluctuations depend exponentially on the inverse noise intensity. Our data are consistent with recent theories on systems driven into bistability that predict generic behaviors different from conventional fluctuation theorems.