BH分子8个Λ-S态和23个Ω态光谱性质的理论研究  

Theoretical study on spectroscopic properties of 8Λ-S and 23Ωstates for BH molecule

作　　者：邢伟[1] 李胜周[1] 孙金锋[2] 李文涛 朱遵略[2] 刘锋 Xing Wei;Li Sheng–Zhou;Sun Jin–Feng;Li Wen–Tao;Zhu Zun–Lüe;Liu Feng(College of Physics and Electronic Engineering,Xinyang Normal University,Xinyang 464000,China;School of Physics,Henan Normal University,Xinxiang 453000,China;Weifang University of Science and Technology,Shouguang 262700,China)

机构地区：[1]信阳师范学院物理电子工程学院,信阳464000 [2]河南师范大学物理学院,新乡453000 [3]潍坊科技学院,寿光262700

出　　处：《物理学报》2022年第10期51-62,共12页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61275132,11274097);河南省自然科学基金(批准号:212300410233);河南省高等学校重点科研项目(批准号:21A140023);信阳师范学院南湖学者奖励计划青年项目资助的课题。

摘　　要：本文利用内收缩多参考组态相互作用方法计算了BH分子8个低电子态(X^(1)∑^(+)、a^(3)∏,A1∏,b^(3)∑-,2^(3)∏,13∑^(+),1^(5)∏-和1^(5)∏)和在自旋-轨道耦合效应下所产生的2^(3)个Ω态的势能曲线、以及X^(1)∑_(0+)^(+),a^(3)∏_(0)+,a^(3)∏_(1),a^(3)∏_(2)和A1∏_(1)态之间6对跃迁的跃迁偶极矩.为了获得精确的势能曲线,计算中修正了单双电子激发、核价相关效应、相对论效应和基组截断带来的误差.获得的BH分子的光谱和跃迁数据与现有的理论值和实验值符合得很好.计算结果表明:BH分子的A1∏_(1)(v’=0-2,J’=1,+)→X^(1)∑_(0+)^(+)(v"=0-2,J"=1,-)跃迁具有较大的爱因斯坦A系数和加权的吸收振子强度、高度对角化分布的振动分支比,A1∏_(1)态具有较短的辐射寿命.另外,a^(3)∏_(0)+和a^(3)∏_(1)态对A1∏_(1)(v’=0)←→X^(1)∑_(0+)^(+)(v"=0)循环跃迁的影响可以忽略.因此,基于A1∏_(1)(v’=0-1,J’=1,+)←→X^(1)∑_(0+)^(+)(v"=0-3,J"=1,-)循环跃迁,我们提出了用一束主冷却激光(λ_(00)=432.45 nm)和两束再泵浦激光(λ_(10)=479.67 nm和λ_(21)=481.40 nm)冷却BH分子的方案,并评价了冷却效果.In this work,the potential energy curves of eight low electronic states(X^(1)∑^(+),a^(3)∏,A^(1)∏,b^(3)∑-,2^(3)∏,1^(3)∑^(+),1^(5)∑-,and 1^(5)∏)and twenty-threeΩstates of BH molecule,and the transition dipole moments among the X^(1)∑_(0+)^(+),a^(3)∏_(0)+,a^(3)∏_(1),a^(3)∏_(2),and A^(1)∏_(1)states are calculated by using the internally contracted multireference configuration interaction(icMRCI)method.In order to obtain the accurate potential energy curve,the errors caused by single and double electron excitation,core-valence correlation effects,relativistic effects and basis set truncation are corrected.The spectral and transition data of BH molecule are in good agreement with the available theoretical and experimental data.The calculation results show that the A^(1)∏_(1)(v’=0-2,J’=1,+)→X^(1)∑_(0+)^(+)(v"=0-2,J"=1,-)transition has large Einstein A-coefficient,weighted absorption oscillator strength,and highly diagonal vibrational branching ratio Rv’v",and the excited state A^(1)∏_(1)(v’=0,1)have short spontaneous radiation lifetimes.Moreover,the effects of a^(3)0+and a^(3)∏_(1)states on A^(1)∏_(1)(v’=0)←→X^(1)∑_(0+)^(+)(v"=0)cycle transition can be ignored.Therefore,according to the A^(1)∏_(1)(v’=0-1,J’=1,+)←→X^(1)∑_(0+)^(+)(v"=0-3,J"=1,-)cycle transition,we propose to apply one main cooling laser(λ00=432.45 nm)and two repumping lasers(λ_(10)=479.67 nm andλ_(21)=481.40 nm)to laser cooling BH molecules,and evaluation of the cooling effect.

关 键 词：势能曲线 光谱常数 自旋-轨道耦合 跃迁偶极矩 

分 类 号：O561.3[理学—原子与分子物理]