Density-induced processes in quantum gas mixtures in optical lattices

Abstract

We show that off-site processes and multi-orbital physics have a crucial impact on the phase diagram of quantum gas mixtures in optical lattices. In particular, we discuss Bose-Fermi mixtures where the intra- and interspecies interactions induce competing density-induced hopping processes, the so-called bond-charge interactions. Furthermore, higher bands strongly influence tunneling and on-site interactions. We apply a multi-orbital interaction-induced dressing of the lowest band which leads to renormalized hopping processes. These corrections give rise to an extended Hubbard model with intrinsically occupation-dependent parameters. The resulting decrease of the tunneling competes with a decrease of the total on-site interaction energy both affecting the critical lattice depth of the superfluid to Mott insulator transition. In contrast to the standard Bose-Fermi-Hubbard model, we predict a large shift of the transition to shallower lattice depths with increasing Bose-Fermi attraction. The applied theoretical model allows an accurate prediction of the modified tunneling amplitudes and the critical lattice depth both recently observed experimentally.

References in corpus (11)

• Bose-Fermi Mixtures in a Three-dimensional Optical Lattice
• Localization of bosonic atoms by fermionic impurities in a 3d optical lattice
• Mixtures of Bosonic and Fermionic Atoms in Optical Lattices
• Role of interactions in 87Rb-40K Bose-Fermi mixtures in a 3d optical lattice
• Spatial correlations of trapped 1d bosons in an optical lattice
• Coherent Interaction of a Single Fermion with a Small Bosonic Field
• Extended Bose Hubbard model of interacting bosonic atoms in optical lattices: from superfluidity to density waves
• Self-Trapping of Bosons and Fermions in Optical Lattices
• Bose-Hubbard model with occupation dependent parameters
• Do mixtures of bosonic and fermionic atoms adiabatically heat up in optical lattices?
• Loss of superfluidity by fermions in the boson Hubbard model on an optical lattice

Cited by in corpus (20)

• Non-standard Hubbard models in optical lattices: a review
• Observation of Density-Induced Tunneling
• Quantum phases in tunable state-dependent hexagonal optical lattices
• Formation of spontaneous density-wave patterns in DC driven lattices
• Hubbard model for atomic impurities bound by the vortex lattice of a rotating BEC
• Wannier functions using a discrete variable representation for optical lattices
• Phase transitions in Bose-Fermi-Hubbard model in the heavy fermion limit: Hard-core boson approach
• Extended Hubbard model describing small multi-dot arrays in bilayer graphene
• Effect of correlated hopping on thermoelectric properties: Exact solutions for the Falicov-Kimball model
• Density-dependent hopping for ultracold atoms immersed in a Bose-Einstein-condensate vortex lattice
• Resonant enhancement of thermoelectric properties by correlated hopping for the Falicov-Kimball model on Bethe lattice
• Staggered quantum phases of dipolar bosons at finite temperatures
• Competing instabilities at long length scales in the one-dimensional Bose-Fermi-Hubbard model at commensurate fillings
• Bose-Hubbard model with random impurities: Multiband and nonlinear hopping effects
• Nonlocal correlations in the optical conductivity spectra
• Many body population trapping in ultracold dipolar gases
• Many-body tunneling in a double-well potential
• Nonstandard Hubbard model and electron pairing
• Thermoelectric properties of Mott insulator with correlated hopping at microdoping
• Miscibility-Immiscibility transition of strongly interacting bosonic mixtures in optical lattices