We report on the production of a ⁴¹K−⁸⁷Rb dual-species Bose-Einstein condensate in a hybrid trap, consisting of a magnetic quadrupole and an optical dipole potential. After loading both atomic species in the trap, we cool down ⁸⁷Rb first by magnetic and then by optical evaporation, while ⁴¹K is sympathetically cooled by elastic collisions with ⁸⁷Rb. We eventually produce two-component condensates with more than 10⁵ atoms and tunable species population imbalance. We observe the immiscibility of the quantum mixture by measuring the density profile of each species after releasing them from the trap.

A. Burchianti, et al.
Dual-species Bose-Einstein condensate of ⁴¹K and ⁸⁷Rb in a hybrid trap
Phys. Rev. A 98, 063616 (2018)