Drift of a polymer chain in disordered media

TL;DR

This paper analyzes the drift behavior of a polymer chain in a disordered medium under an applied force, focusing on fluctuations, size, and velocity without thermal noise, using perturbation theory.

Contribution

It provides the first perturbative calculation of polymer drift properties in disordered media, including fluctuations and size, considering the effects of quenched disorder and applied force.

Findings

Transversal fluctuations are diffusive.

Velocity depends on driving force and polymer length.

Size and fluctuations are affected by disorder and force.

Abstract

We consider the drift of a polymer chain in a disordered medium, which is caused by a constant force applied to the one end of the polymer, under neglecting the thermal fluctuations. In the lowest order of the perturbation theory we have computed the transversal fluctuations of the centre of mass of the polymer, the transversal and the longitudinal size of the polymer, and the average velocity of the polymer. The corrections to the quantities under consideration, which are due to the interplay between the motion and the quenched forces, are controlled by the driving force and the degree of polymerization. The transversal fluctuations of the Brownian particle and of the centre of mass of the polymer are obtained to be diffusive. The transversal fluctuations studied in the present Letter may also be of relevance for the related problem of the drift of a directed polymer in disordered media and its applications.