Dynamical revival of phase coherence in a many-boson system

We study the quantum dynamics of cold Bose atoms in a double well. It is shown that self-trapping, as well as population oscillations are common phenomena associated to nonlinear interactions. For larger U/t, multi-particle tunneling is damped and the quantum dynamics is dominated by the single-particle tunneling. The many-body system can be effectively described in a truncated Fock space. It exhibits coherence-decoherence oscillations in the temporal evolution. We predict a novel phenomenon of dynamical revival and collapse of matter wave fields in optical lattices in regimes near the superfluid-Mott insulator phase boundary.