Event distributions of polymer translocation

TL;DR

This study uses Langevin dynamics simulations to analyze event distributions in polymer translocation, revealing log-normal distributions and suggesting a multiplicative stochastic process underlying the phenomenon.

Contribution

First report of event distributions in polymer translocation, providing new insights into its stochastic characteristics and scaling relations.

Findings

Distributions are log-normal, indicating multiplicative stochastic nature.

Translocation dynamics are similar for forced and unforced cases.

Scaling relations:   for translocation time with polymer length and force.

Abstract

We present event distributions for the polymer translocation obtained by extensive Langevin dynamics simulations. Such distributions have not been reported previously and they provide new understanding of the stochastic characteristics of the process. We extract at a high length scale resolution distributions of polymer segments that continuously traverse through a nanoscale pore. The obtained log-normal distributions together with the characteristics of polymer translocation suggest that it is describable as a multiplicative stochastic process. In spite of its clear out-of-equilibrium nature the forced translocation is surprisingly similar to the unforced case. We find forms for the distributions almost unaltered with a common cut-off length. We show that the individual short-segment and short-time movements inside the pore give the scaling relations $\tau \sim N^\alpha$ and $\tau \sim f^{-\beta}$ for the polymer translocation.