New propagator schemes for explicitly time-dependent Hamiltonians: applications to the multiphoton dissociation dynamics of diatoms

Two propagator methods are proposed for studying the evolution of explicitly time-dependent Hamiltonians. In one case the propagator is constructed by making use of Floquet states while in the other a split operator technique is used. Model applications to the problem of the dissociation of diatoms in strong laser fields prove encouraging. It is found from our numerical experiments that the threshold intensity of the laser field has a unique relationship with the curvature of the potential of the dissociating diatom.