title: Bose-fermi mixtures in a three-dimensional optical lattice.
abstract: We have studied mixtures of fermionic (40)K and bosonic (87)Rb quantum gases in a three-dimensional optical lattice. We observe that an increasing admixture of the fermionic species diminishes the phase coherence of the bosonic atoms as measured by studying both the visibility of the matter wave interference pattern and the coherence length of the bosons. Moreover, we find that the attractive interactions between bosons and fermions lead to an increase of the boson density in the lattice which we measure by studying three-body recombination in the lattice. In our data, we do not observe three-body loss of the fermionic atoms. An analysis of the thermodynamics of a noninteracting Bose-Fermi mixture in the lattice suggests a mechanism for sympathetic cooling of the fermions in the lattice.
authors.affiliation: Institute of Quantum Electronics, ETH Zürich, CH-8093 Zürich, Switzerland.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Günter
authors.forename: Thilo
authors.initials: T
authors.lastname: Stöferle
authors.forename: Henning
authors.initials: H
authors.lastname: Moritz
authors.forename: Michael
authors.initials: M
authors.lastname: Köhl
authors.forename: Tilman
authors.initials: T
authors.lastname: Esslinger