Unifying model of driven polymer translocation

TL;DR

This paper introduces a Brownian dynamics model for driven polymer translocation that incorporates tension propagation effects as a time-dependent friction, accurately matching molecular dynamics simulations and explaining observed scaling behaviors.

Contribution

The paper develops a finite chain length tension propagation formalism that unifies the understanding of driven polymer translocation dynamics.

Findings

Non-equilibrium tension propagation dominates translocation dynamics.

Model results agree with molecular dynamics simulations across parameters.

Explains different scaling laws of translocation time with chain length.

Abstract

We present a Brownian dynamics model of driven polymer translocation, in which non-equilibrium memory effects arising from tension propagation (TP) along the cis side subchain are incorporated as a time-dependent friction. To solve the effective friction, we develop a finite chain length TP formalism, expanding on the work of Sakaue [Sakaue, PRE 76, 021803 (2007)]. The model, solved numerically, yields results in excellent agreement with molecular dynamics simulations in a wide range of parameters. Our results show that non-equilibrium TP along the cis side subchain dominates the dynamics of driven translocation. In addition, the model explains the different scaling of translocation time w.r.t chain length observed both in experiments and simulations as a combined effect of finite chain length and pore-polymer interactions.