Wan Mingjie, Huang Duohui, Shao Juxiang, Yu You, Li Song, Li Yuanyuan
Computational Physics Key Laboratory of Sichuan Province, Yibin University, Yibin 644007, China.
College of Optoelectronic Technology, Chengdu University of Information Technology, Chengdu 610225, China.
J Chem Phys. 2015 Oct 28;143(16):164312. doi: 10.1063/1.4934719.
We present the ab initio study of spin-orbit coupling effects on laser cooling of BeI and MgI molecules. Potential energy curves for the X(2)Σ(+)(1/2), A(2)Π(1/2,3/2), and 2(2)Π(3/2,1/2) states are calculated using multi-reference configuration interaction method plus Davidson corrections. Spectroscopic parameters of BeI and MgI are in excellent agreement with available experimental and theoretical values. The A(2)Π(3/2) state of MgI is a repulsive state. It is an unsuitable scheme for the A(2)Π(3/2)(υ')← X(2)Σ(+)(1/2) (υ″) transition for laser cooling of MgI. Highly diagonally distributed Franck-Condon factors f00 for the A(2)Π(1/2,3/2) (υ' = 0) ← X(2)Σ(+)(1/2) (υ″ = 0) transitions and suitable radiative lifetimes τ for the A(2)Π(1/2,3/2) (υ' = 0) of BeI and MgI are obtained. Three laser wavelength drives are required for the A(2)Π(1/2,3/2)(υ')←X(2)Σ(+)(1/2) (υ″) transitions of BeI and MgI. The proposed cooling wavelengths of BeI and MgI are both in the violet region. The results imply the feasibility of laser cooling of BeI and MgI, and that laser cooling of BeI is more possible.
我们展示了对自旋轨道耦合效应在BeI和MgI分子激光冷却方面的从头算研究。使用多参考组态相互作用方法并加上戴维森修正来计算X(2)Σ(+)(1/2)、A(2)Π(1/2,3/2)和2(2)Π(3/2,1/2)态的势能曲线。BeI和MgI的光谱参数与现有的实验和理论值高度吻合。MgI的A(2)Π(3/2)态是一个排斥态。对于MgI的激光冷却，A(2)Π(3/2)(υ')←X(2)Σ(+)(1/2) (υ″)跃迁是一个不合适的方案。获得了BeI和MgI的A(2)Π(1/2,3/2) (υ' = 0) ← X(2)Σ(+)(1/2) (υ″ = 0)跃迁的高度对角分布的弗兰克 - 康登因子f00以及A(2)Π(1/2,3/2) (υ' = 0)的合适辐射寿命τ。BeI和MgI的A(2)Π(1/2,3/2)(υ')←X(2)Σ(+)(1/2) (υ″)跃迁需要三个激光波长驱动。所提出的BeI和MgI的冷却波长都在紫光区域。结果表明BeI和MgI激光冷却的可行性，并且BeI的激光冷却更有可能实现。
