  The unzipping of a double stranded DNA whose ends are subjected to a time
dependent periodic force with frequency $\omega$ and amplitude $G$ is studied
using Monte Carlo simulations. We obtain the dynamical order parameter, $Q$,
defined as the time average extension between the end monomers of two strands
of the DNA over a period, and its probability distributions $P(Q)$ at various
force amplitudes and frequencies. We also study the time autocorrelations of
extension and the dynamical order parameter for various chain lengths. The
equilibrium force-distance isotherms were also obtained at various frequencies
by using non-equilibrium work measurements.

Soft Condensed Matter;Statistical Mechanics