Abstract

Ground state atomic interactions are crucial to the physics of a gaseous Bose-Einstein condensate (BEG).^1–3 In particular, the magnitude and sign of the scattering length determine the stability and properties of a BEC. The Rb triplet scattering length has been determined,⁴ but more general interactions involving mixed singlet and triplet states are also of interest. Such interactions play a crucial role in the recently observed Rb double condensate.⁵ Also magnetically tunable resonances⁶ may exist, which would allow changes in the scattering length and control over BEG interactions. The ground state potential and specifically the highest lying bound states are crucial to understanding these properties, since small changes in their positions can produce large changes in condensate behavior. We have determined these highest bound states of Rb₂ using double-resonance photoassociation spectroscopy.

© 1997 Optical Society of America