Irreversibility to Reversibility Crossover in Transient Response of an Optically Trapped Particle

TL;DR

This paper investigates the transient dynamics of an optically trapped colloidal particle, revealing a transition from irreversibility to reversibility depending on initial energy, and verifies fluctuation theorems in non-ergodic conditions.

Contribution

It demonstrates the reversible-irreversible crossover in particle relaxation and confirms fluctuation theorems for non-ergodic systems.

Findings

Reversible state achieved at low initial energy.

Irreversible behavior with thermal noise extraction.

Verification of fluctuation theorems in non-ergodic regimes.

Abstract

We study the transient response of a colloidal bead which is released from different heights and allowed to relax in the potential well of an optical trap. Depending on the initial potential energy, the system's time evolution shows dramatically different behaviors. Starting from the short-time reversible to long-time irreversible transition, a stationary reversible state with zero net dissipation can be achieved as the release point energy is decreased. If the system starts with even lower energy, it progressively extracts useful work from thermal noise and exhibits an anomalous irreversibility. In addition, we have verified the Transient Fluctuation Theorem and the Integrated Transient Fluctuation Theorem even for the non-ergodic descriptions of our system.