Hannover 2013 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 12: Quantum gases: Bosons I

Q 12.4: Talk

Monday, March 18, 2013, 15:00–15:15, E 001

Environmentally induced dispersion of otherwise flat-band systems — •Albert Verdeny Vilalta and Andreas Mielke — Institut für Theoretische Physik, Universität Heidelberg, D-69120 Heidelberg, Germany

We investigate the experimental realization of bosonic condensed matter systems with a flat lowest energy band. Such systems can be obtained in optical lattices where shaking permits to engineer the hopping matrix element of the Bose Hubbard model. Since flat band systems are especially sensitive to perturbations, we consider the shaken Bose-Hubbard model coupled linearly to to a bosonic bath (driven Hubbard-Holstein model) so as to take environmental corrections into account. Using the flow equation method of infinitesimal unitary transformations, we construct the effective Hamiltonian of this system. We investigate the changes of its energy spectrum caused by the environment coupling and find a small dispersion as opposed to a perfectly flat band.