title: Role of interactions in 87Rb-40K Bose-Fermi mixtures in a 3D optical lattice.
abstract: We investigate the effect of interspecies interaction on a degenerate mixture of bosonic 87Rb and fermionic 40K atoms in a three-dimensional optical lattice potential. Using a Feshbach resonance, the 87Rb-40K interaction is tuned over a wide range. Through an analysis of the 87Rb momentum distribution, we find a pronounced asymmetry between strong repulsion and strong attraction. In the latter case, we observe a marked shift in the superfluid to Mott insulator transition, which we attribute to a renormalization of the Bose-Hubbard parameters due to self-trapping.
authors.affiliation: Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudinger Weg 7, 55128 Mainz, Germany.
authors.forename: Th
authors.initials: T
authors.lastname: Best
authors.forename: S
authors.initials: S
authors.lastname: Will
authors.forename: U
authors.initials: U
authors.lastname: Schneider
authors.forename: L
authors.initials: L
authors.lastname: Hackermüller
authors.forename: D
authors.initials: D
authors.lastname: van Oosten
authors.forename: I
authors.initials: I
authors.lastname: Bloch
authors.forename: D-S
authors.initials: DS
authors.lastname: Lühmann