An experimental platform for studying the heteronuclear Efimov effect with an ultracold mixture of $^6$Li and $^{133}$Cs atoms

TL;DR

This paper introduces an experimental setup for observing the heteronuclear Efimov effect using an ultracold mixture of lithium-6 and cesium-133 atoms, enabling high-resolution control and detailed study of Efimov states.

Contribution

The paper presents a novel experimental platform with advanced control over heteronuclear interactions, facilitating detailed Efimov effect investigations in ultracold Li-Cs mixtures.

Findings

Successful preparation of ultracold Li-Cs mixtures at 100 nK

High-resolution atom-loss spectroscopy resolving Efimov features

Observation of splitting in Efimov loss features

Abstract

We present the experimental apparatus enabling the observation of the heteronuclear Efimov effect in an optically trapped ultracold mixture of $^6$Li-$^{133}$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$^4$ Cs atoms and 7$\times$ 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.