Preparation of a quantum degenerate mixture of $^{23}$Na$^{40}$K molecules and $^{40}$K atoms

作者：Jin Cao, Huan Yang, Zhen Su, Xinyao Wang, Jun Rui, Bo Zhao, Jian-Wei Pan · 发表于：arXiv (Cornell University) · 年份：2022 · DOI：10.48550/arxiv.2208.09620 · 被引用次数：2 · 研究领域：Cold Atom Physics and Bose-Einstein Condensates、Quantum, superfluid, helium dynamics、Atomic and Subatomic Physics Research

We report on the preparation of a quantum degenerate mixture of $^{23}$Na$^{40}$K molecules and $^{40}$K atoms. A deeply degenerate atomic mixture of $^{23}$Na and $^{40}$K atoms with a large number ratio ($N_F/N_B\approx 6$) is prepared by the mode-matching loading of atoms from a cloverleaf-type magnetic trap into a large-volume horizontal optical dipole trap and evaporative cooling in a large-volume three-beam optical dipole trap. About $3.0\times10^4$ $^{23}$Na$^{40}$K ground-state molecules are created through magneto-association followed by stimulated adiabatic Raman passage. The 2D density distribution of the molecules is fit to the Fermi-Dirac distribution with $T/T_F\approx0.4-0.5$. In the atom-molecule mixture, the elastic collisions provide a thermalization mechanism for the molecules. In a few tens of milliseconds which are larger than the typical thermalization time, the degeneracy of the molecules is maintained, which may be due to the Pauli exclusion principle. The quantum degenerate mixture of $^{23}$Na$^{40}$K molecules and $^{40}$K atoms can be used to study strongly interacting atom-molecule mixtures and to prepare ultracold triatomic molecular gases.