Strongly interacting bosons in a one-dimensional optical lattice at incommensurate densities
Achilleas Lazarides, O. Tieleman, C. Morais Smith
We investigate quantum phase transitions occurring in a system of strongly interacting ultracold bosons in a one-dimensional optical lattice. After discussing the commensurate-incommensurate transition, we focus on the phases appearing at an incommensurate filling. We find a rich phase diagram, with superfluid, supersolid, and solid (kink-lattice) phases. Supersolids generally appear in theoretical studies of systems with long-range interactions; our results break this paradigm and show that they may also emerge in models including only short-range (contact) interactions, provided that quantum fluctuations are properly taken into account.
arXiv:1103.1860•Physical Review A•Aug 16, 2011•8 citations