Self-Trapping of Bosons and Fermions in Optical Lattices

Abstract

We theoretically investigate the enhanced localization of bosonic atoms by fermionic atoms in three-dimensional optical lattices and find a self-trapping of the bosons for attractive boson-fermion interaction. Because of this mutual interaction, the fermion orbitals are substantially squeezed, which results in a strong deformation of the effective potential for bosons. This effect is enhanced by an increasing bosonic filling factor leading to a large shift of the transition between the superfluid and the Mott-insulator phase. We find a nonlinear dependency of the critical potential depth on the boson-fermion interaction strength. The results, in general, demonstrate the important role of higher Bloch bands for the physics of attractively interacting quantum gas mixtures in optical lattices and are of direct relevance to recent experiments with 87Rb - 40K mixtures, where a large shift of the critical point has been found.

4 pages, 4 figures. Published version

References in corpus (6)

• Mixtures of Bosonic and Fermionic Atoms in Optical Lattices
• Instabilities in binary mixtures of one-dimensional quantum degenerate gases
• Mixture of bosonic and spin-polarized fermionic atoms in an optical lattice
• Pairing of 1D Bose-Fermi mixtures with unequal masses
• Do mixtures of bosonic and fermionic atoms adiabatically heat up in optical lattices?
• Localization and delocalization of ultracold bosonic atoms in finite optical lattices

Cited by in corpus (6)

• Role of interactions in 87Rb-40K Bose-Fermi mixtures in a 3d optical lattice
• 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
• Boson Hubbard model with weakly coupled Fermions
• Heteronuclear quantum gas mixtures