Hannover 2003 – wissenschaftliches Programm
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Q: Quantenoptik
Q 35: Quantengase 3: Gruppenberichte
Q 35.3: Gruppenbericht
Donnerstag, 27. März 2003, 12:00–12:30, E001
Observation of Feshbach Resonances in 87 Rb — •Andreas Marte1, Thomas Volz1, Johannes Schuster1, Sebastian Ernst1, Stephan Dürr1, Gerhard Rempe1, Eric G. M. van Kempen2, and Boudewijn J. Verhaar2 — 1Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching, Germany — 2Eindhoven University of Technology, P.O. Box 513, 5600MB Eindhoven, The Netherlands
A cloud of 87Rb atoms in the |f,mf⟩=|1,−1⟩ ground state is evaporatively cooled in a magnetic trap close to or below the BEC transition temperature. The atoms are then transferred into an optical dipole trap made of an Yb:YAG laser operating at a wavelength of 1030 nm. After turning off the magnetic trap, an RF pulse transfers the atoms to the |1,1⟩ Zeeman state. Subsequently, a homogeneous dc magnetic field is applied. We scanned the field range between 0.5 and 1260 Gauss. Four Feshbach resonances have been predicted in this field range [1]. Monitoring the loss of atoms, we observed more than 40 resonances, including the predicted ones [2]. The additional resonances are due to closed channels with rotational quantum number l=2. Such channels were not included in the calculation in [1]. The resonance positions were included in a fit to obtain an improved set of parameters for the rubidium interatomic potential. Although all resonances are narrow, the magnetic field control should be accurate enough to resolve changes in the elastic scattering length on the broadest resonance at 1007 G.
[1] E. van Kempen et al., Phys. Rev. Lett. 88, 93201 (2002).
[2] A. Marte et al., Phys. Rev. Lett. (in press), cond-mat/0210651