No abstract

We precisely measured the binding energy (ǫ bind ) of a molecular state near the Feshbach resonance in a 85 Rb Bose-Einstein condensate (BEC). Rapid magnetic field pulses induced coherent atommolecule oscillations in the BEC. We measured the oscillation frequency as a function of B-field and fit the data to a coupled-channels 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 vDS, vDT , and C6. These results improved our estimate for the stability condition of an attractive BEC. We also found evidence for a mean-field shift to ǫ bind .

We have created vortices in two-component Bose-Einstein condensates. The vortex state was created through a coherent process involving the spatial and temporal control of interconversion between the two components. Using an interference technique, we map the phase of the vortex state to confirm that it possesses angular momentum. We can create vortices in either of the two components and have observed differences in the dynamics and stability.

No abstract