AI 中文总结
该研究利用混合阱中超冷原子的共振电荷交换冷却，实现非激光冷却铯离子6小时稳定囚禁与阈值稳态，突破混合原子-离子系统局限，为相关领域拓展研究提供支撑。
AI 中文摘要
我们报道了在线性保罗阱中，通过与精确居中的超冷铯（Cs）云进行共振电荷交换（RCE）冷却，实现了非激光冷却的铯离子（Cs⁺）的数小时稳定囚禁及稳态。若无冷原子，所有离子会在3分钟内全部损失；而在居中冷原子存在时，RCE冷却可建立起稳定的离子布居，持续6小时无明显衰减，囚禁时长较此前的混合原子-离子系统提升了两个数量级以上。我们观测到离子稳态数量（Nₛ）存在阈值行为：初始离子负载量高于Nₛ时，会向下收敛至Nₛ并保持恒定；初始负载量低于Nₛ时无明显衰减。该动力学由离子-离子射频加热与离子-原子碰撞冷却的竞争关系主导。延长的离子-原子同时囚禁表明，三体复合诱导的Cs₂⁺形成速率常数存在上限：k₃ << 1.4 × 10⁻²⁵ cm⁶ s⁻¹。这一长寿命稳态的实现克服了此前混合原子-离子系统的关键局限，为超冷离子-中性化学、稀有非弹性碰撞及复杂分子离子的协同冷却路径的拓展研究提供了可能。
英文摘要
We report multi-hour stable trapping and steady state of non-laser-coolable Cs$^{+}$ ions in a linear Paul trap, achieved via resonant charge-exchange (RCE) cooling with a precisely centered ultracold Cs cloud. Without cold atoms, all ions are lost within 3 minutes. With centered cold atoms, RCE cooling establishes a stable population of ions for 6 hours with no measurable decay -- more than two orders of magnitude longer hold times compared to prior hybrid atom-ion systems. We observe a threshold behavior in the steady-state number of ions ($N_{s}$): initial ion loadings above $N_{s}$ ions converge downward to $N_{s}$ ions and remain constant thereafter; initial loadings below $N_{s}$ ions show no measurable decay. The dynamics is governed by a competition between ion-ion rf heating and ion-atom collisional cooling. The prolonged, simultaneous ion-atom trapping suggests an upper bound on the three-body recombination-induced Cs$_{2}^{+}$ formation rate constant: $k_{3} << 1.4 \times 10^{-25} cm^{6} s^{-1}$. This remarkable realization of long-lived steady state overcomes a critical limitation of prior hybrid atom-ion systems and enables extended studies of ultracold ion-neutral chemistry, rare inelastic collisions, and sympathetic cooling routes for complex molecular ions.
Comments7 pages, 5 figures
