Be^+离子和Li原子极化率和超极化率的理论研究  

Theoretical study of polarizabilities and hyperpolarizabilities of Be+ions and Li atoms

作　　者：王婷 蒋丽 王霞[1] 董晨钟[1] 武中文[1] 蒋军[1] Wang Ting;Jiang Li;Wang Xia;Dong Chen-Zhong;Wu Zhong-Wen;Jiang Jun(College of Physics and Electronic Engineering,Northwest Normal University,Lanzhou 730070,China)

机构地区：[1]西北师范大学物理与电子工程学院,兰州730070

出　　处：《物理学报》2021年第4期153-162,共10页Acta Physica Sinica

基　　金：国家重点研发计划(批准号:2017YFA0402300);国家自然科学基金(批准号:11774292,11804280,11864036)资助的课题.

摘　　要：利用相对论模型势方法计算了Be^+离子和Li原子的波函数、能级和振子强度,进一步得到了基态的电偶极极化率和超极化率,并详细地分析了不同中间态对基态超极化率的贡献.对于Be^+离子,电偶极极化率和超极化率与已有的理论结果符合得非常好.对于Li原子,电偶极极化率与已有的理论结果符合得很好,但是不同理论方法计算给出的超极化率差别非常大,最大的差别超过了一个数量级.通过分析不同中间态对Li原子基态超极化率的贡献,解释了不同理论结果之间有较大差异的原因.The wave functions,energy levels,and oscillator strengths of Be+ions and Li atoms are calculated by using a relativistic potential model,which is named the relativistic configuration interaction plus core polarization method(RCICP).The calculated energy levels in this work are in good agreement with experimental levels tabulated in NIST Atomic Spectra Database,and the difference appears in the sixth digit after the decimal point.The present oscillator strengths are in good agreement with the existing theoretical and experimental results.By means of these energy levels and oscillator strengths,the electric-dipole static polarizabilities and hyperpolarizabilities of the ground states are determined.The contributions of different intermediate states to the hyperpolarizabilities of the ground state are further discussed.For Be+ions,the present electric-dipole polarizability and hyperpolarizability are in good agreement with the results calculated by Hartree-Fock plus core polarization method,the finite field method and relativistic many-body method.The largest contribution to the hyperpolarizability is the term ofα0^1β0.For Li atoms,the present electric-dipole polarizability is in good agreement with the available theoretical and experimental results.However,the present hyperpolarizability is different from the other theoretical results significantly.Moreover,the hyperpolarizabilities calculated by different theoretical methods are quite different.The biggest difference is more than one order of magnitude.In order to explain the reason for these differences,we analyze the contributions of different intermediate states to the hyperpolarizability in detail.It is found that the sum of the contributions of the 2s→npj(n≥3)and npj→ndj(n≥3)to hyperpolarizability is approximately equal to that term ofα0^1β0.The total hyperpolarizability,which is the difference between the sum of the contributions of the 2s→npj(n≥3)and npj→ndj(n≥3)to hyperpolarizability andα0^1β0,is relatively small.Consequently,this dif

关 键 词：电偶极极化率 超极化率 Be+离子 LI原子 相对论模型势方法 

分 类 号：O562[理学—原子与分子物理]