Multiorbital bosons in bipartite optical lattices
2012 (English)In: Physical Review A. Atomic, Molecular, and Optical Physics, ISSN 1050-2947, E-ISSN 1094-1622, Vol. 86, no 2, 023611- p.Article in journal (Refereed) Published
We study interacting bosons in a two-dimensional square bipartite optical lattice. By focusing on the regime where the first three excited bands are nearly degenerate (i.e., the first-excited p bands in one sublattice are nearly degenerate with the s band of the other sublattice), we derive a multi-orbital tight-binding model which captures the most relevant features of the band structure. In addition, we also derive a corresponding generalized Bose-Hubbard model and solve it numerically under different situations, both with and without a confining trap. It is especially found that the hybridization between sublattices can strongly influence the phase diagrams and, in a trap, enable even appearances of condensed phases intersecting the same Mott insulating plateaus.
Place, publisher, year, edition, pages
2012. Vol. 86, no 2, 023611- p.
IdentifiersURN: urn:nbn:se:su:diva-81568DOI: 10.1103/PhysRevA.86.023611ISI: 000307382200007OAI: oai:DiVA.org:su-81568DiVA: diva2:563309