Volume 88, Number 6, December 2009
Article Number 68006
Number of page(s) 6
Section Interdisciplinary Physics and Related Areas of Science and Technology
Published online 01 January 2010
EPL, 88 (2009) 68006
DOI: 10.1209/0295-5075/88/68006

Driven polymer translocation through nanopores: Slow-vs.-fast dynamics

K. Luo1, 2, T. Ala-Nissila3, 4, S.-C. Ying4 and R. Metzler1

1   Physics Department, Technical University of Munich - D-85748 Garching, Germany, EU
2   Department of Polymer Science and Engineering and CAS Key Laboratory of Soft Matter Chemistry University of Science and Technology of China - Hefei, Anhui 230026, China
3   Department of Applied Physics and COMP Center of Excellence, Helsinki University of Technology P.O. Box 1100, FIN-02015 TKK, Espoo, Finland, EU
4   Department of Physics, Brown University, P.O. Box 1843, Providence, RI 02912, USA

received 27 August 2009; accepted in final form 25 November 2009; published December 2009
published online 4 January 2010

We investigate the dynamics of polymer translocation through nanopores under external driving by 3D Langevin Dynamics simulations, focusing on the scaling of the average translocation time $\tau $ vs. the length of the polymer, $\tau \sim N^{\alpha}$. For slow translocation, i.e., under low driving force and/or high friction, we find $\alpha \approx 1+\nu \approx$ 1.588, where $\nu $ denotes the Flory exponent. In contrast, $\alpha \approx$ 1.37 is observed for fast translocation due to the highly deformed chain conformation on the trans side, reflecting a pronounced non-equilibrium situation. The dependence of the translocation time on the driving force is given by $\tau $ ~ F-1 and $\tau $ ~ F-0.80 for slow and fast translocation, respectively. These results clarify the controversy on the magnitude of the scaling exponent $\alpha $ for driven translocation.

87.15.A- - Theory, modeling, and computer simulation.
87.15.H- - Dynamics of biomolecules.
36.20.-r - Macromolecules and polymer molecules.

© EPLA 2009