In recent years, there has been notable progress in the preparation and control of ultracold gases of diatomic molecules. The next experimental challenge is the production of ultracold polyatomic molecular gases. Here, we report the creation of an ultracold gas of 23 Na 40 K 2 triatomic molecules from a mixture of ground-state sodium-23–potassium-40 ( 23 Na 40 K) molecules and potassium-40 ( 40 K) atoms. The triatomic molecules were created by adiabatic magneto-association through an atom–diatomic molecule Feshbach resonance. We obtained clear evidence for the creation of triatomic molecules by directly detecting them using radio-frequency dissociation. Approximately 4000 triatomic molecules with a high-peak phase-space density of 0.05 could be created. The ultracold triatomic molecules can serve as a launchpad to probe the three-body potential energy surface and may be used to prepare quantum degenerate triatomic molecular gases.

中文翻译：

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从原子-双原子分子混合物中产生三原子分子的超冷气体

近年来，双原子分子超冷气体的制备和控制取得了显着进展。下一个实验挑战是超冷多原子分子气体的生产。在这里，我们报告了超冷气体的产生23钠40钾2个来自基态 sodium-23–potassium-40 (23钠40K) 分子和 potassium-40 (40K) 原子。三原子分子是通过原子-双原子分子 Feshbach 共振通过绝热磁缔合产生的。通过使用射频解离直接检测三原子分子，我们获得了创建三原子分子的明确证据。可以创建大约 4000 个三原子分子，其峰值相空间密度为 0.05。超冷三原子分子可作为发射台探测三体势能面，可用于制备量子简并三原子分子气体。