Theoretical study of laser cooling of magnesium monofluoride using ab initio methods
Theoretical study of laser cooling of magnesium monofluoride using ab initio methods
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从头算法激光冷却一氟化镁的理论研究
DOI：
10.1103/physreva.91.042511
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发表时间：
2015-04-28
影响因子：
2.9
通讯作者：
Jiang, Gang
中科院分区：
文献类型：
--
作者：
Kang, Shuying;Gao, Yufeng;Jiang, Gang
用从头算方法对激光冷却(MgF)-Mg-24-F-19分子的可行性进行了理论研究。低空电子态由多参考构型相互作用（MRCI）方法确定，其中Davidson修正（+Q）和Douglas-Kroll-Hess标量相对论修正也被考虑在内。计算得到的光谱常数与现有的实验数据非常吻合。通过计算A(2)Pi(nu') -> X-2 Sigma(+)（nu）跃迁的势能曲线和跃迁偶极矩，验证了Franck-Condon因子（ffs）、辐射寿命和辐射宽度。我们的计算表明，A(2)Pi(nu' = 0) -> X-2 Sigma(+) （nu = 0）跃迁提供了高度对角线分布的ffs （f(00) = 0.917）和A(2)Pi（nu' = 0）态的短辐射寿命（tau = 7.96 ns），足以实现快速激光冷却。所需的冷却波长在紫外线区域。一个综合方案证明了激光冷却MgF的可能性。此外，在MRCI水平上证实C-2 Sigma（+）态为Rydberg态，与实验猜想相符。B-2 π和D-2 Sigma（+）态也有报道，但迄今为止尚未观察到。
A theoretical investigation of the feasibility of laser-cooling the (MgF)-Mg-24-F-19 molecule is performed using ab initio calculations. The low-lying electronic states are determined by the multireference configuration-interaction (MRCI) method, where the Davidson modification (+Q) with the Douglas-Kroll-Hess scalar relativistic correction is also taken into account. The calculated spectroscopic constants are in excellent agreement with the available experimental data. The Franck-Condon factors (FCFs), radiative lifetimes, and radiative widths are verified by calculating the potential energy curves and the transition dipole moment of the A(2)Pi(nu') -> X-2 Sigma(+)(nu) transition. Our calculation indicates that the A(2)Pi(nu' = 0) -> X-2 Sigma(+) (nu = 0) transition provides highly diagonally distributed FCFs (f(00) = 0.917) and a short radiative lifetime (tau = 7.96 ns) for the A(2)Pi(nu' = 0) state, which is short enough for rapid laser cooling. The required cooling wavelengths are in the ultraviolet region. A comprehensive scheme demonstrates the possibility of laser-cooling MgF. Moreover, the C-2 Sigma(+) state is confirmed to be a Rydberg state at the MRCI level, which is in line with experimental conjecture. The B-2 Pi and D-2 Sigma(+) states are also reported, but they have not been observed to date.