Relaxation of a Colloidal Particle into a Nonequilibrium Steady State

TL;DR

This study investigates how a colloidal particle relaxes between nonequilibrium steady states, revealing that relaxation times match steady state measurements and increase with driving force, supported by experimental and theoretical results.

Contribution

It demonstrates experimentally and theoretically that relaxation times in a driven colloidal system match steady state relaxation times and increase with nonequilibrium driving.

Findings

Relaxation time equals steady state relaxation time.

Relaxation time increases with driving away from equilibrium.

Experimental results agree with theoretical predictions.

Abstract

We study the relaxation of a single colloidal sphere which is periodically driven between two nonequilibrium steady states. Experimentally, this is achieved by driving the particle along a toroidal trap imposed by scanned optical tweezers. We find that the relaxation time after which the probability distributions have been relaxed is identical to that obtained by a steady state measurement. In quantitative agreement with theoretical calculations the relaxation time strongly increases when driving the system further away from thermal equilibrium.