Work distribution functions in polymer stretching experiments

TL;DR

This paper analyzes the distribution of work done during the stretching of a Gaussian polymer, providing explicit calculations for Rouse dynamics and exploring implications for fluctuation theorems.

Contribution

It presents explicit formulas for work distribution in polymer stretching, including cases constrained by end position or force, and discusses connections to fluctuation theorems.

Findings

Work distribution is Gaussian for Rouse dynamics.

Explicit mean and width of the work distribution are derived.

Connections to Jarzynski's equality are discussed.

Abstract

We compute the distribution of the work done in stretching a Gaussian polymer, made of N monomers, at a finite rate. For a one-dimensional polymer undergoing Rouse dynamics, the work distribution is a Gaussian and we explicitly compute the mean and width. The two cases where the polymer is stretched, either by constraining its end or by constraining the force on it, are examined. We discuss connections to Jarzynski's equality and the fluctuation theorems.