Translocation dynamics of a short polymer driven by an oscillating force

We study the translocation dynamics of a short polymer moving in a noisy environment and drivenby an oscillating force. The dynamics is numerically investigated by solving a Langevin equationin a two-dimensional domain. We consider a phenomenological cubic potential with a metastablestate to model the polymer-pore interaction and the entropic free energy barrier characterizing thetranslocation process. The mean first translocation time of the center of inertia of polymers showsa nonmonotonic behavior, with a minimum, as a function of the number of the monomers. Thedependence of the mean translocation time on the polymer chain length shows a monotonicallyincreasing behavior for high values of the number of monomers. Moreover, the translocation timeshows a minimum as a function of the frequency of the oscillating forcing field for all the polymerlengths investigated. This finding represents the evidence of the resonant activation phenomenon inthe dynamics of polymer translocation, whose occurrence is maintained for different values of thenoise intensity.