Hannover 2010 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 16: Quantum Gases: Interaction Effects I

Q 16.5: Vortrag

Dienstag, 9. März 2010, 15:15–15:30, E 001

Parameterizing the influence of Feshbach resonances for photoassociation and in the context of the Bose-Hubbard model of ultracold atoms in optical lattices. — •Philipp-Immanuel Schneider — AG Moderne Optik, Institut für Physik, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin

Ultracold atoms interacting in the presence of a Feshbach resonance (FR) have a vast range of applications from the creation of strong correlations in ultracold gases to the formation of dipolar ultracold molecules. Here we present an extension of the Bose-Hubbard (BH) model for ultracold atoms in optical lattices interacting with large scattering lengths as they appear in FRs. We show by an exact numerical treatment that the BH Hamiltonian can reproduce the two-particle spectrum for arbitrary large scattering lengths only by replacing the original interaction parameter U. The optimal value of this parameter can be well approximated by an analytic expression. Furthermore, we study the enhancement of photoassociation in the presence of an FR. We find that one can describe the transition rate of the complex photoassociation process by only two parameters, the maximal transition rate and the position of vanishing transition rate. It is shown that the latter determines the maximal enhancement of the transition rate.