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Preparation of a quasi-two-dimensional Bose mixture of ultracold Na23 and Rb87 atoms

Ji-Kai Liao1,2, Hao-Ran Zhang1,2, Xiao-Rong Yu1,2, Ya-Qun Qi1,2, Yi-Cheng Guo1,2, Bo Zhao1,2,3, Jun Rui1,2,3, and Jian-Wei Pan1,2,3

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Phys. Rev. A 114, 023303 – Published 3 August, 2026

DOI: https://doi.org/10.1103/tr78-m3jb

Abstract

Quantum gases confined in reduced dimensions have enabled the observation of many exotic quantum phenomena. While existing experiments primarily focus on homonuclear systems, we report here on the efficient preparation of a quasi-two-dimensional heteronuclear quantum degenerate mixture of ultracold Na23 and Rb87. We describe the apparatus design and detail the procedures for preparing the two-dimensional (2D) quantum mixture. The apparatus has several unique features, including compact and modular 2D magneto-optical trap sources, a science chamber that accommodates various lattice geometries, a precision in-vacuum electrode assembly, and high-resolution imaging for both atomic species. After loading the dual-species condensate into a single layer of a vertical optical lattice, we prepare a 2D gas mixture and observe quantum immiscibility in the in situ equilibrium density profiles. The observed density profiles reasonably agree with mean-field theories. The apparatus provides a versatile platform for investigating several interesting problems, including quantum impurities, quantum droplets, and polar molecules in low dimensions.

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Phys. Rev. A 114, 023303– Published 3 August, 2026
  • Received 20 April 2026
  • Accepted 7 July 2026
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