Dynamical Scaling Exponents for Polymer Translocation through a Nanopore

Abstract

We determine the scaling exponents of polymer translocation (PT) through a nanopore by extensive computer simulations of various microscopic models for chain lengths extending up to N=800 in some cases. We focus on the scaling of the average PT time $\tau \sim N^{\alpha}$ and the mean-square change of the PT coordinate $<s^2(t)> \sim t^\beta$. We find $\alpha=1+2\nu$ and $\beta=2/\alpha$ for unbiased PT in 2D and 3D. The relation $\alpha \beta=2$ holds for driven PT in 2D, with crossover from $\alpha \approx 2\nu$ for short chains to $\alpha \approx 1+\nu$ for long chains. This crossover is, however, absent in 3D where $\alpha = 1.42 \pm 0.01$ and $\alpha \beta \approx 2.2$ for $N \approx 40-800$.