  We employ the time-dependent non-crossing approximation to investigate the
joint effect of strong electron-electron and electron-phonon interaction on the
instantaneous conductance of a single molecule transistor which is abruply
moved into the Kondo regime by means of a gate voltage. We find that the
instantaneous conductance exhibits decaying sinusoidal oscillations in the long
timescale for infinitesimal bias. Ambient temperature and electron-phonon
coupling strength influence the amplitude of these oscillations. The frequency
of oscillations is found to be equal to the phonon frequency. We argue that the
origin of these oscillations can be attributed to the interference between the
emerging Kondo resonance and its phonon sidebands. We discuss the effect of
finite bias on these oscillations.
