激光冷却氯化锶分子的理论研究  

Theoretical Study on Laser Cooling of Strontium Chloride Molecules

作　　者：韩玉龙 程冬[2,3] 孙辉 孙金芳 周宝航 凤尔银 Han Yulong;Cheng Dong;Sun Hui;Sun Jinfang;Zhou Baohang;Feng Eryin(General Education&Foreign Language College,Anhui Institute of Information Technology,Wuhu,Anhui 241000,China;College of Physics and Electronic Information,Anhui Normal University,Wuhu,Anhui 241000,China;Wuhu School Affiliated to Beijing Normal University,Wuhu,Anhui 241000,China)

机构地区：[1]安徽信息工程学院通识教育与外国语学院,安徽芜湖241000 [2]安徽师范大学物理与电子信息学院,安徽芜湖241000 [3]北京师范大学芜湖附属学校,安徽芜湖241000

出　　处：《激光与光电子学进展》2022年第7期49-56,共8页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(11374014);安徽高校自然科学研究项目(KJ2019A1298)。

摘　　要：采用Davidson矫正(+Q)的内收缩多参考组态相互作用方法,计算了SrCl分子两个最低解离限Sr(^(1)S_(g))+Cl(^(2)P_(u))和Sr(^(3)P_(u))+Cl(^(2)P_(u))对应的7个Λ-S态(X^(2)Σ^(+)、B^(2)Σ^(+)、C^(2)Δ、F^(2)Σ^(+)、A^(2)∏、D^(2)∏和E^(2)∏)的势能曲线。基于计算的势能曲线,求解一维Schr?dinger方程,得到了基态和几个较低激发态的光谱常数,这些结果与已报道的实验和理论结果符合得较好。基于振动波函数和A^(2)∏-X^(2)Σ^(+)跃迁偶极矩,理论得到了SrCl分子的Franck-Condon因子以及辐射寿命。结果表明,A^(2)∏-X^(2)Σ^(+)跃迁具有较高的对角化Franck-Condon因子(f_(00)=0.96959)和较短的辐射寿命(τ=31.05 ns),符合激光冷却分子的基本条件。给出了利用3束激光冷却SrCl分子的光循环方案,其中主泵浦光波长为668.2 nm,辅泵浦光波长为682.0 nm和681.5 nm。The potential energy curves for seven Λ-S electronic states(X~2Σ^(+),B~2Σ^(+),C~2Δ,F~2Σ^(+),A~2∏,D~2∏,and E~2∏) of strontium chloride(SrCl) molecule are investigated using the multireference configuration interaction method(MRCI).Davidson correction(+Q),core-valence correction,and spin-orbit coupling effect are considered in the calculation.Based on the obtained potential energy curves of Λ-S states,the vibration energy levels,wave functions,and spectroscopic parameters are determined by solving the Schr?dinger equation using the discrete position presentation method.The calculated values agree substantially with experimental and theoretical values.Additionally,the transition dipole moments,Franck-Condon factors,and radiative lifetime of the SrCl molecule are explored.Due to the significant diagonal distribution of the Franck-Condon factors(f00=0.96959) and short radiative lifetimes(τ=31.05 ns) of the A~2∏(ν′=0) →X~2Σ^(+)(ν″=0) transition,the SrCl molecules are suitable for rapid laser cooling.Therefore,this study presents a three-laser scheme for laser cooling of SrCl molecules.The calculated pump and repump wavelengths of the laser-driven cycling are 668.2 nm(λ_(00)),682.0 nm(λ_(01)),and 681.5 nm(λ_(12)).

关 键 词：原子与分子物理学 激光冷却 SrCl分子 FRANCK-CONDON因子 辐射寿命 

分 类 号：O561.5[理学—原子与分子物理]