Düsseldorf 2007 – wissenschaftliches Programm
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Q: Fachverband Quantenoptik und Photonik
Q 37: Quantengase (Tunneln I)
Q 37.2: Vortrag
Mittwoch, 21. März 2007, 12:30–12:45, 6J
Correlated tunneling dynamics of atom pairs in double wells — •Simon Fölling1, Patrick Cheinet1, Stefan Trotzky1, Artur Widera1, Torben Müller2, and Immanuel Bloch1 — 1Inst. für Physik, Johannes Gutenberg-Universität, D-55099 Mainz — 2Institute for Quantum Electronics, ETH Zürich, CH-8093 Zürich
The interplay between the atom-atom interaction and the mobility is the dominant parameter governing the dynamics of many strongly correlated systems of ultracold atoms. The most elementary realization of such a system is a set of two potential wells occupied by two interacting atoms which can tunnel through the central barrier. By superimposing the periodic potentials of two standing light waves with a periodicity of 382.5nm and 765nm and controllable relative intensity and phase, we create a one-dimensional array of double wells with adjustable tunnel coupling. Additional standing waves on the two orthogonal axes provide axial confinement, creating a three-dimensional array of up to 105 double wells occupied by one to two 87Rb atoms each. By initially loading only one side of each double well before initiating the tunneling dynamics, we can directly observe the dynamics of single atoms as well as of atom pairs. Since the ratio of the tunneling matrix element J and the on-site repulsive interaction U between two atoms can be modified in a wide range, the crossover from a tunneling- to an interaction-dominated regime can be observed. Here, the independent motion of two atoms changes to a correlated tunnel process of the pairs.