title: Quantum Engineering of a Low-Entropy Gas of Heteronuclear Bosonic Molecules in an Optical Lattice.
abstract: We demonstrate a generally applicable technique for mixing two-species quantum degenerate bosonic samples in the presence of an optical lattice, and we employ it to produce low-entropy samples of ultracold ^{87}Rb^{133}Cs Feshbach molecules with a lattice filling fraction exceeding 30%. Starting from two spatially separated Bose-Einstein condensates of Rb and Cs atoms, Rb-Cs atom pairs are efficiently produced by using the superfluid-to-Mott insulator quantum phase transition twice, first for the Cs sample, then for the Rb sample, after nulling the Rb-Cs interaction at a Feshbach resonance's zero crossing. We form molecules out of atom pairs and characterize the mixing process in terms of sample overlap and mixing speed. The dense and ultracold sample of more than 5000 RbCs molecules is an ideal starting point for experiments in the context of quantum many-body physics with long-range dipolar interactions.
authors.affiliation: Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria.
authors.forename: Lukas
authors.initials: L
authors.lastname: Reichsöllner
authors.affiliation: Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schindewolf
authors.affiliation: Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria.|Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria.
authors.forename: Tetsu
authors.initials: T
authors.lastname: Takekoshi
authors.affiliation: Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria.|Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, 6020 Innsbruck, Austria.
authors.forename: Rudolf
authors.initials: R
authors.lastname: Grimm
authors.affiliation: Institut für Experimentalphysik, Universität Innsbruck, 6020 Innsbruck, Austria.
authors.forename: Hanns-Christoph
authors.initials: HC
authors.lastname: Nägerl