Reaction blockading in a reaction between an excited atom and a charged molecule at low collision energy
Reaction blockading in a reaction between an excited atom and a charged molecule at low collision energy
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DOI：
10.1038/s41557-019-0264-3
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发表时间：
2019-05
期刊：
影响因子：
21.8
通讯作者：
P. Puri;Michael Mills;I. Simbotin;J. Montgomery;R. Côté;Christian Schneider;A. Suits;E. Hudson
中科院分区：
文献类型：
--
作者：
P. Puri;Michael Mills;I. Simbotin;J. Montgomery;R. Côté;Christian Schneider;A. Suits;E. Hudson
利用原子-离子混合俘获系统研究了低温下激发态原子-极性分子离子化学反应（Ca+ BaCl）。的反应速率和产物的分支分数进行测量和比较模型计算作为原子量子态和碰撞能量的函数。在最低的碰撞能量，我们发现，化学动力学显着不同的捕获理论的预测，主要是由辐射寿命的原子量子态，而不是底层的激发态相互作用势。我们提供了一个简单的规则，计算在什么温度下达到这个制度，其中碰撞复杂的寿命比量子态的辐射寿命长。这种效应极大地抑制了短寿命激发态的反应性，为直接探测反应范围提供了一种手段。它还自然地抑制混合捕获实验中不需要的化学反应，允许更长的分子离子相干性和询问时间。
We study an excited atom-polar molecular ion chemical reaction (Ca+ BaCl) at low temperature by utilizing a hybrid atom-ion trapping system. The reaction rate and product branching fractions are measured and compared to model calculations as a function of both atomic quantum state and collision energy. At the lowest collision energy we find that the chemical dynamics dramatically differ from capture theory predictions and are primarily dictated by the radiative lifetime of the atomic quantum state instead of the underlying excited-state interaction potential. We provide a simple rule for calculating at what temperature this regime, where the collision complex lifetime is longer than the radiative lifetime of the quantum state, is reached. This effect, which greatly suppresses the reactivity of short-lived excited states, provides a means for directly probing reaction range. It also naturally suppresses unwanted chemical reactions in hybrid trapping experiments, allowing longer molecular ion coherence and interrogation times.