Inner-shell excitation in the YbF molecule and its impact on laser cooling
Inner-shell excitation in the YbF molecule and its impact on laser cooling
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YbF分子内壳层激发及其对激光冷却的影响
DOI：
10.1016/j.jms.2022.111625
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发表时间：
2022
影响因子：
1.4
通讯作者：
Tarbutt, Michael R.
中科院分区：
文献类型：
--
作者：
Zhang, Chi;Zhang, Chaoqun;Cheng, Lan;Steimle, Timothy C.;Tarbutt, Michael R.
YbF分子是测量电子电偶极矩的灵敏系统。这种测量的精度可以通过直接激光冷却分子到超冷温度来提高。然而，由4f电子激发产生的低电子态可能会阻碍激光冷却。其中一组“4f空穴”态位于用于激光冷却的A2 <$1/2激发态之下，即使分支比小到1 0− 5，辐射衰减到这些中间能级也是一个障碍。其他的4f空穴态非常接近于A 2 Π 1/2态，并且微扰导致了激光冷却循环中所涉及的混合特征的状态。这种扰动可能会增强分子到激光冷却循环之外的状态的损失。我们模拟了A2 <$1/2态的微扰，以确定态之间的耦合强度，解扰势能曲线，以及基态X2 <$+的各种振动能级的辐射分支比。用电子结构计算方法计算了4f空穴态及其与A2 Π 1/2和X2 π +态之间的跃迁强度.我们确定了冷却循环的泄漏，其分支比约为5× 1 0− 4，主要由4f空穴态的基态构型的贡献决定。最后，我们评估这些结果的影响，激光冷却的YbF和具有类似结构的分子。
The YbF molecule is a sensitive system for measuring the electron’s electric dipole moment. The precision of this measurement can be improved by direct laser cooling of the molecules to ultracold temperature. However, low-lying electronic states arising from excitation of a 4f electron may hinder laser cooling. One set of these “4f hole” states lies below the A 2 Π 1/2 excited state used for laser cooling, and radiative decay to these intermediate levels, even with branching ratios as small as 1 0− 5, can be a hindrance. Other 4f hole states lie very close to the A 2 Π 1/2 state, and a perturbation results in states of mixed character that are involved in the laser cooling cycle. This perturbation may enhance the loss of molecules to states outside of the laser cooling cycle. We model the perturbation of the A 2 Π 1/2 state to determine the strength of the coupling between the states, the de-perturbed potential energy curves, and the radiative branching ratios to various vibrational levels of the ground state, X 2 Σ+. We use electronic structure calculations to characterise the 4f hole states and the strengths of transitions between these states and the A 2 Π 1/2 and X 2 Σ+ states. We identify a leak out of the cooling cycle with a branching ratio of roughly 5× 1 0− 4, dominated by the contribution of the ground state configuration in a 4f hole state. Finally, we assess the impact of these results for laser cooling of YbF and molecules with similar structure.
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影响因子：
19.6
作者：
S. Truppe;H. Williams;M. Hambach;L. Caldwell;N. Fitch;E. Hinds;B. Sauer;M. Tarbutt
通讯作者：
S. Truppe;H. Williams;M. Hambach;L. Caldwell;N. Fitch;E. Hinds;B. Sauer;M. Tarbutt
DOI：
10.1002/cphc.201600656
发表时间：
2016-11-18
期刊：
Chemphyschem : a European journal of chemical physics and physical chemistry
影响因子：
--
作者：
Fitch NJ;Tarbutt MR
通讯作者：
Tarbutt MR
DOI：
10.1039/f29757100728
发表时间：
1975
期刊：
Journal of the Chemical Society, Faraday Transactions
影响因子：
--
作者：
R. F. Barrow;A. Chojnicki
通讯作者：
A. Chojnicki
影响因子：
3.3
作者：
Augenbraun, Benjamin L.;Lasner, Zack D.;Doyle, John M.
通讯作者：
Doyle, John M.
YbF 和 YbCl 的化学发光光谱
影响因子：
1.4
作者：
Henry U. Lee;R. Zare
通讯作者：
R. Zare