Multiband and nonlinear hopping corrections to the three-dimensional Bose-Fermi-Hubbard model

Journal Article · Wed Jun 15 04:00:00 EDT 2011 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.83.063630· OSTI ID:21550175

Mering, Alexander; Fleischhauer, Michael ^[1]

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1. Fachbereich Physik and Research Center for Optics and Material Sciences, Technische Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany)

Recent experiments revealed the importance of higher-band effects for the Mott-insulator(MI)-superfluid transition(SF) of ultracold bosonic atoms or mixtures of bosons and fermions in deep optical lattices [Best et al., Phys. Rev. Lett. 102, 030408 (2009); Will et al., Nature (London) 465, 197 (2010)]. In the present work we derive an effective lowest-band Hamiltonian in three dimensions that generalizes the standard Bose-Fermi-Hubbard model taking these effects as well as nonlinear corrections of the tunneling amplitudes mediated by interspecies interactions into account. It is shown that a correct description of the lattice states in terms of the bare-lattice Wannier functions, rather than approximations such as harmonic-oscillator states, is essential. In contrast to self-consistent approaches based on effective Wannier functions, our approach captures the observed reduction of the superfluid phase for repulsive interspecies interactions.

• OSTI ID: 21550175
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 83; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AMPLITUDES
APPROXIMATIONS
ATOMS
BOSONS
CALCULATION METHODS
CONSTRUCTIVE FIELD THEORY
CORRECTIONS
CRYSTAL MODELS
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATORS
EQUIPMENT
FERMIONS
FIELD THEORIES
HAMILTONIANS
HARMONIC OSCILLATORS
HUBBARD MODEL
LATTICE FIELD THEORY
MATHEMATICAL MODELS
MATHEMATICAL OPERATORS
NONLINEAR PROBLEMS
QUANTUM FIELD THEORY
QUANTUM OPERATORS
SUPERFLUIDITY
THREE-DIMENSIONAL CALCULATIONS
TUNNEL EFFECT