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 with nonlinear interactions. For larger U/t, multiparticle tunneling is damped and the quantum dynamics is dominated by 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 an interesting phenomenon of dynamical revival and collapse of matter wave fields in optical lattices in regimes near the superfluid-Mott-insulator phase boundary.