Some aspects of polymer translocation dynamics through nanopore: comparison of recent the theories with simulation results*

Translocation of a flexible poymer chain through a narrow pore has still remained an active field of research. Earlier theoretical studies of Sung and Park,\footnote{W. Sung and P.~J. Park, Phys. Rev. Lett. {\bf 77}, 783 (1996).} Muthukumar,\footnote{M. Muthukumar, J. Chem. Phys. {\bf 111}, 10371 (1999).} Chuang, Kantor and Kardar, Kantor and Kardar\footnote{J. Chuang, Y. Kantor and M. Kardar, Phys. Rev. E {\bf 65}, 011802 (2001); Y. Kantor and M. Kardar, \textit{ibid.} {\bf 69}, 021806 (2004).} for a flexible chain have been complemented by more recent theories of Sakaue\footnote{T. Sakaue, Phys. Rev. E {\bf 76}, 021803 (2007); \textit{ibid.} \textbf{81}, 041808 (2010).} where tension propagation(TP) along the chain backbone at the $cis$ side resulting in a nonuniform stretching of the chain has been proposed to be a key input for theoretical studies. Recently these elements of the TP theory has been incorporated in to a Brownian dynamics (BDTP) scheme and numerical studies of the equations of motion are in excellent agreement with prior simulation studies.\footnote{T. Ikonen, A. Bhattacharya, T. Ala-Nissila and W. Sung (submitted).} A driven translocating chain is essentially \textit{out-of-equilibrium}\footnote{A. Bhattacharya and Kurt Binder, Phys. Rev. E. \textbf{81}, 041804 (2010); A. Bhattacharya \textit{et al.}, Eur. Phys. J. E \textbf{29}, 423 (2009).} which results in \textit{cis-trans} asymmetries both in ocnformations and in dynamics. Therefore, results from theoretical studies should capture these features. In this talk first I will first present results from Langevin dynamics simulation citing several cases where how this \textit{cis-trans} asymmetry affects the chain conformations and the translocation dynamics. Then I will dicuss relevance of these results in the context of exisiting theories.