An Experimental Platform for Studying the Heteronuclear Efimov Effect with an Ultracold Mixture of $$^\textbf{6}$$Li and $$^\textbf{133}$$Cs Atoms

Abstract

We present the experimental apparatus enabling the observation of the heteronuclear Efimov effect in an optically trapped ultracold mixture of $$^6$$ 6 Li-$$^{133}$$ 133 Cs with high-resolution control of the interactions. A compact double-species Zeeman slower consisting of four interleaving helical coils allows for a fast-switching between two optimized configurations for either Li or Cs and provides an efficient sequential loading into their respective MOTs. By means of a bichromatic optical trapping scheme based on species-selective trapping we prepare mixtures down to 100 nK of $${1\times 10^{4}}$$ 1 × 10 4 Cs atoms and $${7\times 10^{3}}$$ 7 × 10 3 Li atoms. Highly stable magnetic fields allow high-resolution atom-loss spectroscopy and enable to resolve splitting in the loss feature of a few tens of milligauss. These features allowed for a detailed study of the Efimov effect.