Overlapping Bose-Einstein condensates of 23Na and 133Cs

We report on the creation of dual-species Bose-Einstein condensates (BECs) of Na-23 atoms and Cs-133 atoms. We demonstrate sympathetic cooling of Cs with Na in a magnetic quadrupole trap and a crossed optical dipole trap, leading to Na BECs with 8(1) x 10(5) atoms and Cs BECs with 3.5(1) x 10(4) atoms. Investigating cross thermalization and lifetimes of the mixture, we find that the Na and Cs BECs are miscible and overlapping, interacting with a moderate interspecies scattering length of 18(4) a(0) at 23 G and 29(4) a(0) at 894 G and coexisting for tens of seconds. Overlapping condensates of Na and Cs offer possibilities for many-body physics with ultracold bosonic mixtures and constitute an ideal starting point for the creation of ultracold ensembles of NaCs ground-state molecules.

Automated summary

The researchers successfully created dual-species Bose-Einstein condensates of Na-23 and Cs-133 atoms, demonstrating miscibility and overlap between the Na and Cs BECs with moderate interspecies scattering lengths. The overlapping condensates offer possibilities for many-body physics with ultracold bosonic mixtures and serve as an ideal starting point for the creation of ultracold ensembles of NaCs ground-state molecules.