Polymer dynamics in time-dependent periodic potentials

TL;DR

This paper investigates the behavior of discrete polymers in time-dependent periodic potentials, revealing complex nonlinear dynamics, current inversions, and enhanced transport coherence depending on polymer type and length.

Contribution

It introduces a master equation approach to analyze polymer dynamics in time-dependent potentials, including stochastic and deterministic switching mechanisms, and explores effects on drift and diffusion.

Findings

Rich nonlinear behavior of drift and diffusion coefficients.

Current inversions caused by rebound effects in polymers with internal structure.

Increased transport coherence for longer polymers.

Abstract

Dynamics of a discrete polymer in time-dependent external potentials is studied with the master equation approach. We consider both stochastic and deterministic switching mechanisms for the potential states and give the essential equations for computing the stationary state properties of molecules with internal structure in time-dependent periodic potentials on a lattice. As an example, we consider standard and modified Rubinstein-Duke polymers and calculate their mean drift and effective diffusion coefficient in the two-state non-symmetric flashing potential and symmetric traveling potential. Rich non-linear behavior of these observables is found. By varying the polymer length, we find current inversions caused by the rebound effect that is only present for molecules with internal structure. These results depend strongly on the polymer type. We also notice increased transport coherence for longer polymers.