Direct observation of bimolecular reactions of ultracold KRb molecules
Direct observation of bimolecular reactions of ultracold KRb molecules
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DOI：
10.1126/science.aay9531
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发表时间：
2019-11-29
期刊：
影响因子：
56.9
通讯作者：
Ni, K. -K.
中科院分区：
文献类型：
--
作者：
Hu, M. -G.;Liu, Y.;Ni, K. -K.
飞化学技术在获得探测化学反应中瞬态中间体所需的短时间尺度方面发挥了重要作用。在这项研究中，我们采用了一种对比的方法，通过在超低温下制备处于最低振动量子态的反应物分子来延长中间体的寿命，从而显着减少了它们相互碰撞时可进入的出口通道的数量。在500纳米开尔文的温度下，利用电离光谱和速度图成像技术，我们直接观察了反应(KRb)-K-40-Rb-87 + (KRb)-K-40-Rb-87 (sic) K2Rb2 * (sic) K-2 + Rb-2的反应物、中间体和产物。除了观察到长寿命、能量丰富的中间复合物之外，这项技术还为进一步研究超冷状态下的量子态分解反应动力学打开了大门。
Femtochemistry techniques have been instrumental in accessing the short time scales necessary to probe transient intermediates in chemical reactions. In this study, we took the contrasting approach of prolonging the lifetime of an intermediate by preparing reactant molecules in their lowest rovibronic quantum state at ultralow temperatures, thereby markedly reducing the number of exit channels accessible upon their mutual collision. Using ionization spectroscopy and velocity-map imaging of a trapped gas of potassium-rubidium (KRb) molecules at a temperature of 500 nanokelvin, we directly observed reactants, intermediates, and products of the reaction (KRb)-K-40-Rb-87 + (KRb)-K-40-Rb-87 (sic) K2Rb2 * (sic) K-2 + Rb-2. Beyond observation of a long-lived, energy-rich intermediate complex, this technique opens the door to further studies of quantum-state-resolved reaction dynamics in the ultracold regime.