极性双原子分子精细结构及激光冷却的研究：以GaH分子为例

Cold and untralcold molecules are of growing interest due to their prospective and wide applications which can be used as attractive candidates for quantum systems, quantum computation. Selection of appropriate diatomic molecules is the primary problem of laser cooling. Therefore, this project on potential candidates that meet certain criteria for laser cooling would be an important research topic. The objective of this project is to study the structural features and spectroscopic transition properties of GaH and GaH+ polar molecules. It concretely aims at the key scientific problems regarding the suitability of these three ionic molecules for laser cooling and the design of a visible laser-cooling cycle from theoretical study. Using the multi-reference configuration interaction method based on the quantum chemical ab initio calculations, the main research content of this project includes three aspects as follow: 1) the fine-structural features of GaH and GaH+ polar molecules; 2) the spectroscopic transition property of the GaH and GaH+ polar molecules; 3) the suitability of GaH and GaH+ polar molecules for laser cooling; 4) the laser-cooling scheme of the potential laser cooling candidates which could provide the wavelength and numerical of the required pumping laser and repumping laser; 5) the preliminary evaluation of the Doppler cooling temperature and the rebound temperature of the laser-cooling candidate. This research is not only to explore the structural properties and spectroscopic transition properties, but also provides valuable theoretical basis on understanding the feasibility of laser cooling of GaH and GaH+ polar molecules from a microscopic point of view which have been not prepared at present experiment. It has important scientific significance in the development of the cross field between atomic and molecular physics and high accuracy precision measurement techniques.

激光冷却分子的制备与相关的理论研究是当代原子分子物理学最重要的前沿领域之一。本项目以极性双原子分子为研究对象，采用基于从头算量子化学的多参考组态相互作用方法围绕GaH和GaH+分子的光谱跃迁辐射性质和激光冷却该类分子的微观机理及其可行性这些关键性科学问题展开研究。研究内容包括： GaH和GaH+分子较低几个电子态的光谱的精细结构性质；以及电子态之间的光谱跃迁性质，例如跃迁偶极矩、弗兰克-康登因子、跃迁波长以及自发辐射寿命等；对所研究的分子体系的激光冷却的微观机理及其可行性进行理论分析；并对可进行激光冷却的候选激光冷分子提出具体的激光冷却方案，包括泵浦激光和重泵浦激光的波长和具体条数；对候选的激光冷却分子的多普勒冷却温度和反弹温度做出初步的评估。本项目可为探明目前实验尚未制备的极性分子提供有价值的理论参考，这对推动冷分子相关的高精度的精密测量技术和原子分子物理的交叉发展具有重要的科学意义。

激光冷却分子的制备与相关的理论研究是当代原子分子物理学最重要的前沿领域之一。本项目以极性双原子分子为研究对象，采用基于从头算量子化学的多参考组态相互作用方法围绕GaH和GaH+分子的光谱跃迁辐射性质和激光冷却该类分子的微观机理及其可行性这些关键性科学问题展开研究。研究内容包括：GaH和GaH+分子较低几个电子态的光谱的精细结构性质；以及电子态之间的光谱跃迁性质，例如跃迁偶极矩、弗兰克-康登因子、跃迁波长以及自发辐射寿命等；对所研究的分子体系的激光冷却的微观机理及其可行性进行理论分析；结果显示激光冷却GaH分子的难度较大，而GaH+分子是潜在的激光冷分子，并对激光冷分子GaH+提出具体的激光冷却方案，包括泵浦激光和重泵浦激光的波长和具体条数；同时对GaH+激光冷却分子的多普勒冷却温度和反弹温度也做出了初步的评估。本项目可为探明目前实验尚未制备的极性分子提供有价值的理论参考，这对推动冷分子相关的高精度的精密测量技术和原子分子物理的交叉发展具有重要的科学意义。