Boson Hubbard model with weakly coupled Fermions

Abstract

Using an imaginary-time path integral approach, we develop the perturbation theory suited to the boson Hubbard model, and apply it to calculate the effects of a dilute gas of spin-polarized fermions weakly interacting with the bosons. The full theory captures both the static and the dynamic effects of the fermions on the generic superfluid-insulator phase diagram. We find that, in a homogenous system described by a single-band boson Hubbard Hamiltonian, the intrinsic perturbative effect of the fermions is to generically suppress the insulating lobes and to enhance the superfluid phase.

4 pages, 1 figure; final version as published in PRB

References in corpus (3)

• Self-Trapping of Bosons and Fermions in Optical Lattices
• Mixture of bosonic and spin-polarized fermionic atoms in an optical lattice
• Do mixtures of bosonic and fermionic atoms adiabatically heat up in optical lattices?

Cited by in corpus (4)

• Supersolidity of cold-atom Bose-Fermi mixtures in optical lattices
• Generalized Dynamical Mean-Field Theory for Bose-Fermi Mixtures in Optical Lattices
• Loss of superfluidity by fermions in the boson Hubbard model on an optical lattice
• Effects of a dilute gas of fermions on the superfluid-insulator phase diagram of the Bose-Hubbard model