title: Observation of density-induced tunneling.
abstract: We study the dynamics of bosonic atoms in a tilted one-dimensional optical lattice and report on the first direct observation of density-induced tunneling. We show that the interaction affects the time evolution of the doublon oscillation via density-induced tunneling and pinpoint its density and interaction dependence. The experimental data for different lattice depths are in good agreement with our theoretical model. Furthermore, resonances caused by second-order tunneling processes are studied, where the density-induced tunneling breaks the symmetric behavior for attractive and repulsive interactions predicted by the Hubbard model.
authors.affiliation: Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
authors.forename: Ole
authors.initials: O
authors.lastname: Jürgensen
authors.affiliation: Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria.
authors.forename: Florian
authors.initials: F
authors.lastname: Meinert
authors.affiliation: Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria.
authors.forename: Manfred J
authors.initials: MJ
authors.lastname: Mark
authors.affiliation: Institut für Experimentalphysik und Zentrum für Quantenphysik, Universität Innsbruck, 6020 Innsbruck, Austria.
authors.forename: Hanns-Christoph
authors.initials: HC
authors.lastname: Nägerl
authors.affiliation: Institut für Laser-Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
authors.forename: Dirk-Sören
authors.initials: DS
authors.lastname: Lühmann