Critical evaluation of the computational methods used in the forced polymer translocation

TL;DR

This paper critically examines computational methods in forced polymer translocation, revealing artifacts in Monte Carlo simulations and demonstrating that the scaling exponent depends on force and initial conditions, challenging previous assumptions.

Contribution

It identifies artifacts in Monte Carlo methods affecting force scaling and shows that the scaling exponent varies with force and initial polymer configuration.

Findings

Monte Carlo artifacts can distort force scaling results.

The scaling exponent $eta$ depends on force $f$, not being universal.

Translocation dynamics can be explained by a simple force balance.

Abstract

In forced polymer translocation, the average translocation time, $\tau$, scales with respect to pore force, $f$, and polymer length, $N$, as $\tau \sim f^{-1} N^{\beta}$. We demonstrate that an artifact in Metropolis Monte Carlo method resulting in breakage of the force scaling with large $f$ may be responsible for some of the controversies between different computationally obtained results and also between computational and experimental results. Using Langevin dynamics simulations we show that the scaling exponent $\beta \le 1 + \nu$ is not universal, but depends on $f$. Moreover, we show that forced translocation can be described by a relatively simple force balance argument and $\beta$ to arise solely from the initial polymer configuration.