Studying a dual-species BEC with tunable interactions

Papp, S. B.; Pino, J. M.; Wieman, C. E.

Studying a dual-species BEC with tunable interactions

Authors

Papp, S. B.

Pino, J. M.

Wieman, C. E.

Description

We report on the observation of controllable spatial separation in a dual-species Bose-Einstein condensate (BEC) with $^{85}$Rb and $^{87}$Rb. Interparticle interactions between the different components can change the miscibility of the two quantum fluids. In our experiments, we clearly observe the immiscible nature of the two simultaneously Bose-condensed species via their spatial separation. Furthermore the $^{85}$Rb Feshbach resonance near 155 G is used to change them between miscible and immiscible by tuning the $^{85}$Rb scattering length. Our apparatus is also able to create $^{85}$Rb condensates with up to $8\times10^4$ atoms which represents a significant improvement over previous work.