类锂离子体系自旋四重态费米接触项的精密计算  

High precision calculations of Fermi contact term for lithium-like ions

作　　者：魏向杰 孙邓 王黎明 严宗朝 Wei Xiang-Jie;Sun Deng;Wang Li-Ming;Yan Zong-Chao(School of Physics,Henan Normal University,Xinxiang 453007,China;Department of Physics,University of New Brunswick,Fredericton E3B 5A3,Canada)

机构地区：[1]河南师范大学物理学院,新乡453007 [2]Department of Physics,University of New Brunswick,Fredericton E3B 5A3,Canada

出　　处：《物理学报》2022年第20期39-45,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11774080)资助的课题。

摘　　要：费米接触项与原子超精细结构常数有密切关系,往往对原子能级的超精细劈裂起主要贡献.波函数在原点处的行为以及电子之间的关联效应是影响费米接触项计算精度的两个主要因素.对于一般的原子体系来说,费米接触项的高精度计算不是一件容易的工作.本文利用Hylleraas坐标下的Rayleigh-Ritz变分法求解了锂原子和类锂离子体系(Z=4—10)自旋四重态1s2s3s^(4)S,1s2s4s^(4)S和1s2s2p^(4)P的薛定谔方程,得到的非相对论变分能量收敛精度达到10^(-13).根据所得到的高精度变分波函数,计算了这些体系的费米接触项,并研究了原子核的有限质量对结果的影响.费米接触项的精度达到了10^(-10).本文结果可以作为其他理论方法的参考基准,同时也为相关的实验研究提供了参考数据.The Fermi contact term is closely related to the atomic hyperfine constants.It often dominates the hyperfine splittings.The quality of the wave function near the origin and the correlation effect between electrons are two main factors which affect the numerical accuracy of the Fermi contact term.It is not an easy task to compute the Fermi contact term with high precision for a general atom.In the present paper,the Schr?dinger equations of the 1s2s3s^(4)S,1s2s4s^(4)S and 1s2s2p^(4)P states of lithium atom and lithium-like ions(Z=4-10)are solved by using Rayleigh-Ritz variational method in Hylleraas coordinates.The variational energiesenergy converges to an accuracy of 10^(-13).Then the Fermi contact terms for these states are calculated based on the high precision variation wave functions.In particular,the Drachman global method are adopted in order to improve the convergence of the Fermi contact term.The effect of finite nuclear mass on Fermi contact term,i.e.the first-order mass polarization coefficient is also calculated.The Fermi contact term converges to an accuracy of 10^(-10),which is the most accurate result at present.Our results can be used as a reference for other theoretical methods or relevant experimental studies.

关 键 词：类锂离子 费米接触项 Hylleraas坐标 变分法 

分 类 号：O469[理学—凝聚态物理]