Production of a dual-species Bose-Einstein condensate of Rb and Cs atoms
  We report the simultaneous production of Bose-Einstein condensates (BECs) of $^{87}$Rb and $^{133}$Cs atoms in separate optical traps. The two samples are mixed during laser cooling and loading but are separated by $400 \mu$m 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. 
A. D. Lercher and T. Takekoshi and M. Debatin and B. Schuster and R.   Rameshan and F. Ferlaino and R. Grimm and H.-C. N\"agerl
cond-mat.quant-gas