Pairing and density-wave phases in Boson-Fermion mixtures at fixed filling

Abstract

We study a mixture of fermionic and bosonic cold atoms on a two-dimensional optical lattice, where the fermions are prepared in two hyperfine (isospin) states and the bosons have Bose-Einstein condensed (BEC). The coupling between the fermionic atoms and the bosonic fluctuations of the BEC has similarities with the electron-phonon coupling in crystals. We study the phase diagram for this system at fixed fermion density of one per site (half-filling). We find that tuning of the lattice parameters and interaction strengths (for fermion-fermion, fermion-boson and boson-boson interactions) drives the system to undergo antiferromagnetic ordering, s-wave and d-wave pairing superconductivity or a charge density wave phase. We use functional renormalization group analysis where retardation effects are fully taken into account by keeping the frequency dependence of the interaction vertices and self-energies. We calculate response functions and also provide estimates of the energy gap associated with the dominant order, and how it depends on different parameters of the problem.

5 pages, 3 figures

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Cited by in corpus (11)

• A finite-frequency functional RG approach to the single impurity Anderson model
• Supersolid Bose-Fermi Mixtures in Optical Lattices
• Supersolidity of cold-atom Bose-Fermi mixtures in optical lattices
• p-Wave superfluid and phase separation in atomic Bose-Fermi mixture
• Generalized Dynamical Mean-Field Theory for Bose-Fermi Mixtures in Optical Lattices
• Interactions mediated by atoms, photons, electrons, and excitons
• Phases and collective modes of hardcore Bose-Fermi mixture in an optical lattice
• Superfluid-Insulator Transition and Fermion Pairing in Bose-Fermi Mixtures
• Correlated Phases of Population Imbalanced Fermi-Fermi Mixtures on an Optical Lattice
• The Functional Renormalization Group for Zero-Dimensional Quantum Systems in and out of Equilibrium
• Exploring phonon-like interactions in one-dimensional Bose-Fermi mixtures