Overlapping Dual Species Bose-Einstein Condensates of Lithium and Cesium

Yi Dong Chen^1*, W.-X. Li¹, Y.-T. Sun¹, Q.-C. Chen¹, P.-Y. Chang¹, S. Tung¹

¹Department of Physics, National Tsing Hua University, Hsinchu, Taiwan

* Presenter:Yi Dong Chen, email:asw5926@yahoo.com.tw

We report on the successful creation of overlapping dual-species Bose-Einstein condensates (BECs) of ⁷Li and ¹³³Cs. These condensates are generated in a bichromatic optical dipole trap formed by the superposition of 1550-nm and 780-nm laser beams. During the production process, we administer an external magnetic field of 886 G to finely tune the scattering lengths a_Li to 484a₀, a_Cs to 123a₀, and a_LiCs to 248a₀. These optimized parameters not only enable efficient forced evaporation and sympathetic cooling but also lead to an immiscible phase between the two BECs. The resulting quantum mixtures typically feature population numbers of N_Li approximately 6 × 10³ and N_Cs approximately 1.5 × 10⁴.

Keywords: Quantum gases, Ultracold atoms, Bose Einstein Condensates