Noise driven translocation of short polymers in crowded solutions

TL;DR

This paper investigates how thermal noise affects the translocation dynamics of short polymers crossing potential barriers, revealing nonmonotonic behaviors and different regimes influenced by polymer length and noise intensity.

Contribution

It introduces an enhanced Rouse model incorporating Lennard-Jones interactions and bending torque to study noise-driven polymer translocation in two dimensions.

Findings

Mean first passage time shows nonmonotonic dependence on polymer length at low noise.

Thermal fluctuations induce two distinct translocation regimes.

Polymer length significantly influences translocation times under noise effects.

Abstract

In this work we study the noise induced effects on the dynamics of short polymers crossing a potential barrier, in the presence of a metastable state. An improved version of the Rouse model for a flexible polymer has been adopted to mimic the molecular dynamics by taking into account both the interactions between adjacent monomers and introducing a Lennard-Jones potential between all beads. A bending recoil torque has also been included in our model. The polymer dynamics is simulated in a two-dimensional domain by numerically solving the Langevin equations of motion with a Gaussian uncorrelated noise. We find a nonmonotonic behaviour of the mean first passage time and the most probable translocation time, of the polymer centre of inertia, as a function of the polymer length at low noise intensity. We show how thermal fluctuations influence the motion of short polymers, by inducing two different regimes of translocation in the molecule transport dynamics. In this context, the role played by the length of the molecule in the translocation time is investigated.