Hamburg 2009 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 22: Quantengase: Fermionen im Gitter

Q 22.7: Talk

Tuesday, March 3, 2009, 15:45–16:00, VMP 6 HS-A

Doublon relaxation in the Fermi-Hubbard model — •Niels Strohmaier, Daniel Greif, Robert Jördens, Leticia Tarruell, Henning Moritz, and Tilman Esslinger — Institute for Quantum Electronics, ETH Zürich, Switzerland

The investigation of interacting quantum many-particle systems in non-equilibrium has recently attracted a lot of attention. However, a theoretical understanding of experimental results remains challenging due to the complexity of the systems. Ultracold atoms in optical lattices, well described by the Hubbard model, offer a new approach. Their cleanliness and the unique tunability of parameters make them well suited for the emulation of condensed matter systems.

We report on our latest experiments with repulsively interacting Fermions in a 3D optical lattice. Starting either from a Mott insulator or from a metallic state, we perturb the sample by generating a significant amount of doubly occupied lattice sites. The following relaxation of the system back to its thermal equilibrium is monitored in time-resolved manner. We study this decay of doublons for a wide range of parameters of the Fermi-Hubbard Hamiltonian and observe a clear dependence on the ratio of interaction energy and kinetic energy.