da Silva H, Kendrick B K, Li H, Kotochigova S, Balakrishnan N
Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Nevada 89154, United States.
Theoretical Division (T-1, MS B221), Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States.
J Phys Chem Lett. 2025 Jun 19;16(24):6171-6177. doi: 10.1021/acs.jpclett.5c01083. Epub 2025 Jun 11.
The K + KRb → Rb + K chemical reaction is the first ultracold atom-diatom chemical reaction for which experimental results have been reported for temperatures below 1 μK more than a decade ago. The reaction occurs through coupling with an excited electronic state that is accessible even in the ultracold limit. A previous quantum dynamics study, excluding nonadiabatic effects, has reported a rate coefficient that is about 35% below the experimental value. Here, we report the first nonadiabatic quantum dynamics study of this reaction and obtain rate coefficients in better agreement with experiments. Our results show that short-range dynamics mediated by coupling with the excited electronic state introduces quantum interference effects that influence both the state-to-state rate coefficients and the overall reaction rates.
K + KRb → Rb + K 化学反应是首个报道了温度低于1 μK时实验结果的超冷原子 - 双原子化学反应，该实验结果早在十多年前就已公布。该反应通过与一个即使在超冷极限下也可及的激发电子态耦合而发生。之前一项排除了非绝热效应的量子动力学研究报告的速率系数比实验值低约35%。在此，我们报告了该反应的首个非绝热量子动力学研究，并获得了与实验结果更相符的速率系数。我们的结果表明，与激发电子态耦合介导的短程动力学引入了量子干涉效应，这对态 - 态速率系数和整体反应速率均有影响。
