arXiv:1201.1008 · Physical Review Letters

Preparation and Spectroscopy of a Metastable Mott-Insulator State with Attractive Interactions

Manfred J. Mark, Elmar Haller, Katharina Lauber, Johann Georg Danzl, A. Janisch, Hans Peter Büchler, Andrew J. Daley, Hanns‐Christoph Nägerl

Published May 25, 2012• 63 citations

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Abstract

We prepare and study a metastable attractive Mott-insulator state formed with bosonic atoms in a three-dimensional optical lattice. Starting from a Mott insulator with Cs atoms at weak repulsive interactions, we use a magnetic Feshbach resonance to tune the interactions to large attractive values and produce a metastable state pinned by attractive interactions with a lifetime on the order of 10 s. We probe the (de)excitation spectrum via lattice modulation spectroscopy, measuring the interaction dependence of two- and three-body bound-state energies. As a result of increased on-site three-body loss we observe resonance broadening and suppression of tunneling processes that produce three-body occupation.

DOI: 10.1103/physrevlett.108.215302

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