2004/07/31 by P. Buonsante, Pierfrancesco Buonsante, Vittorio Penna +2 · 4 citations
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #Quantum, superfluid, helium dynamics #cond-mat.stat-mech
paper · pdf · doi:10.1103/physreva.70.061603
published as Phys. Rev. A 70, 061603 (2004) · 5 pages, 3 figures; final version; bibliography updated; acknowledgments included
openalex publication_date 2004/12/23 · arxiv created 2005/01/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The zero-temperature phase diagram of a Bose-Einstein condensate confined in realistic one-dimensional \mathit\ensuremathℓ-periodic optical superlattices is investigated. The system of interacting bosons is modeled in terms of a Bose-Hubbard Hamiltonian whose site-dependent local potentials and hopping amplitudes reflect the periodicity of the lattice partition in \mathit\ensuremathℓ-site cells. Relying on the exact mapping between the hardcore limit of the boson Hamiltonian and the model of spinless noninteracting fermions, incompressible insulator domains are shown to exist for rational fillings that are predicted to be compressible in the atomic limit. The corresponding boundaries, qualitatively described in a multiple-site mean-field approach, are shown to exhibit an unusual loophole shape. A more quantitative description of the loophole domain boundaries at half filling for the special case \mathit\ensuremathℓ=2 is supplied in terms of analytic strong-coupling expansions and quantum Monte Carlo simulations.