From Superfluid to Mott Insulator

Manuel Endres

Ian B. Spielman, J. H. Huckans, Jennifer Sebby-Strabley +4 more

M. Iskin

The standard mean-field theory for the Mott-insulator--superfluid phase transition is not sufficient to describe the Mott-insulator--paired-superfluid phase transition. Therefore, by restricting the two-species Bose-Hubbard Hamiltonian to the subspace of paired particles, and using perturbation theory, here we derive an analytic mean-field expression for the Mott-insulator--paired-superfluid transition boundary.

Jay Deep Sau, Bin Wang, S. Das Sarma

Mott-insulator-to-superfluid quenches have been used by recent experiments to generate exotic superfluid phases. While the final Hamiltonian following the sudden quench is that of a superfluid, it is not a priori clear whether the final state of the system actually enters the superfluid phase. To understand the nature of the final state the temporal evolution of the momentum distribution is calculated following a Mott-insulator-to-superfluid quench. Using the numerical infinite time-evolving block decimation approach and the analytical rotor model approximation it is established that the one- and two-dimensional Mott insulators following the quench equilibrate to thermal states with spatially short-ranged coherence peaks in the final momentum distribution and therefore are not superfluids. However, in three dimensions a divergence in the momentum distribution indicating the emergence of true superfluid order is found.

Tilman Esslinger

Florian Gebhard