Driven polymer translocation through a cylindrical nanochannel: Interplay between the channel length and the chain length

TL;DR

This study combines analytical methods and Langevin simulations to explore how the length of a nanochannel and a polymer chain influence translocation times, revealing different regimes and a minimum translocation time at specific channel-to-chain length ratios.

Contribution

It provides a detailed analysis of the interplay between channel length and polymer length in translocation dynamics, highlighting new regimes and the existence of a translocation time minimum.

Findings

Translocation time scales as N^{1+ν} for short channels under weak force.

Translocation time scales as F^{-1}L for long channels, independent of N.

A minimum translocation time occurs at a specific L/N ratio.

Abstract

Using analytical techniques and Langevin dynamics simulations, we investigate the dynamics of polymer translocation through a nanochannel embedded in two dimensions under an applied external field. We examine the translocation time for various ratio of the channel length $L$ to the polymer length $N$. For short channels $L\ll N$, the translocation time $\tau \sim N^{1+\nu}$ under weak driving force $F$, while $\tau\sim F^{-1}L$ for long channels $L\gg N$, independent of the chain length $N$. Moreover, we observe a minimum of translocation time as a function of $L/N$ for different driving forces and channel widths. These results are interpreted by the waiting time of a single segment.