title: Superfluidity of interacting bosonic mixtures in optical lattices.
abstract: We report the observation of many-body interaction effects for a homonuclear bosonic mixture in a three-dimensional optical lattice with variable state dependence along one axis. Near the superfluid-to-Mott insulator transition for one component, we find that the presence of a second component can reduce the apparent superfluid coherence, most significantly when the second component either experiences a strongly localizing lattice potential or none at all. We examine this effect by varying the relative populations and lattice depths, and discuss the observed behavior in view of recent proposals for atomic-disorder and polaron-induced localization.
authors.affiliation: Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794-3800, USA. bgadway@ic.sunysb.edu
authors.forename: Bryce
authors.initials: B
authors.lastname: Gadway
authors.forename: Daniel
authors.initials: D
authors.lastname: Pertot
authors.forename: René
authors.initials: R
authors.lastname: Reimann
authors.forename: Dominik
authors.initials: D
authors.lastname: Schneble