Dual-species Bose-Einstein condensates of ⁷Li and ¹³³Cs

We report the creation of dual-species Bose-Einstein condensates (BECs) of Li-7 and Cs-133. These BECs are formed in a bichromatic optical dipole trap created with 1550- and 780-nm laser beams. During the production process, an external magnetic field of 886 G is applied to adjust the scattering lengths to a(Cs) = 123a(0), a(Li) = 484a(0), and a(LiCs) = 248a(0). These scattering lengths allow for efficient evaporation and sympathetic cooling. The dual-species BECs are typically produced with 1.5 x 10(4) Cs atoms and 6.0 x 10(3) Li atoms. This quantum degenerate mixture of Li and Cs provides an ideal platform for exploring phenomena such as polarons and Efimov trimers, as well as for creating ground-state LiCs molecules.