2012/03/31 by Jani-Petri Martikainen, J.-P. Martikainen, Jonas Larson · 18 citations
Chemistry · Mathematics · Physics and Astronomy · #Bipartite graph #Bose–Hubbard model #Boson #Cold Atom Physics and Bose-Einstein Condensates #Combinatorics #Condensed matter physics #Degenerate energy levels #Electronic band structure #Excited state #Graph #Hubbard model #Ising model #Lattice (music) #Mathematics #Optical lattice #Phase (matter) #Phase diagram #Physics #Quantum mechanics #Spectroscopy and Laser Applications #Square lattice #Strong Light-Matter Interactions #Superconductivity #Superfluidity #cond-mat.quant-gas #quant-ph
paper · pdf · doi:10.1103/physreva.86.023611
published in Physical Review A 86(2) (American Physical Society) · Minor changes
openalex publication_date 2012/08/10 · arxiv created 2012/08/17 · arxiv updated 2012/08/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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.