Production of a dual-species Bose-Einstein condensate of Rb and Cs atoms

We report the simultaneous production of Bose-Einstein condensates (BECs) of ⁸⁷Rb and ¹³³Cs atoms in separate optical traps. The two samples are mixed during laser cooling and loading but are separated by 400 μm for the final stage of evaporative cooling. This is done to avoid considerable interspecies three-body recombination, which causes heating and evaporative loss. We characterize the BEC production process, discuss limitations, and outline the use of the dual-species BEC in future experiments to produce rovibronic ground state molecules, including a scheme facilitated by the superfluid-to-Mott-insulator (SF-MI) phase transition.