Candidates for direct laser cooling of diatomic molecules with the simplest 1Σ-1Σ electronic system
Candidates for direct laser cooling of diatomic molecules with the simplest 1Σ-1Σ electronic system
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使用最简单的 (1)Sigma-(1)Sigma 电子系统直接激光冷却双原子分子的候选方案
DOI：
10.1103/physreva.97.062501
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发表时间：
2018-06-05
影响因子：
2.9
通讯作者：
Liu, Jinjun
中科院分区：
文献类型：
--
作者：
Li, Chuanliang;Li, Yachao;Liu, Jinjun
本文提出利用（1）σ-（1）σ电子跃迁系统直接激光冷却异质双原子分子。AgH，以及它的氘同位素AgD，被用作一个例子来说明冷却方案。势能曲线和相关的分子参数的AgH和AgD，包括自旋轨道常数和电子跃迁偶极矩，确定在内部收缩的多构型参考配置相互作用计算。通过计算预测的A（1）Sigma（+）-X-1 Sigma（+）跃迁的高度对角化的Franck-Condon矩阵表明存在准闭环跃迁，这使得这些分子适合于直接激光冷却。通过数值求解速率方程，我们证明了AgH和AgD分子都可以在大约20 ms内从25 K冷却到2 mK。我们的研究阐明并支持了最简单的（1）Sigma-（1）Sigma系统中的分子可以作为直接激光冷却的有利候选者的假设。
We propose to utilize the (1)Sigma-(1) Sigma electronic transition system for direct laser cooling of heteronuclear diatomic molecules. AgH, as well as its deuterium isotopolog AgD, is used as an example to illustrate the cooling schemes. Potential-energy curves and relevant molecular parameters of both AgH and AgD, including the spin-orbit constants and the electronic transition dipole moments, are determined in internally contracted multiconfiguration-reference configuration interaction calculations. The highly diagonal Franck-Condon matrices of the A(1)Sigma(+)-X-1 Sigma(+) transitions predicted by the calculations suggest the existence of quasi-closed-cycle transitions, which renders these molecules suitable for direct laser cooling. By solving rate equations numerically, we demonstrated that both AgH and AgD molecules can be cooled from 25 K to 2 mK temperature in approximately 20 ms. Our investigation elucidates and supports the hypothesis that molecules in the simplest (1)Sigma-(1) Sigma system can serve as favorable candidates for direct laser cooling.