Physical Review A
We precisely measured the binding energy (εbind) of a molecular state near the Feshbach resonance in a 85Rb Bose-Einstein condensate (BEC). Rapid magnetic-field pulses induced coherent atom-molecule oscillations in the BEC. We measured the oscillation frequency as a function of B field and fit the data to a coupled-channel model. Our analysis constrained the Feshbach resonance position [155.041(18) G], width [10.71(2) G], and background scattering length [−443(3)a0] and yielded new values for the Rb interaction parameters. These results improved our estimate for the stability condition of an attractive BEC. We also found evidence for a mean-field shift to εbind.
Claussen, Neil R.; Kokkelmans, S. J. J. M. F.; Thompson, Sarah T.; Donley, Elizabeth A.; and Cornell, Eric A., "Very High Precision Bound State Spectroscopy near a 85Rb Feshbach Resonance" (2003). Physics Faculty Contributions. 18.