氦原子2~3S—2~3P精密光谱研究  

Precision spectroscopy on the 2~3S–2~3P transition of atomic helium

作　　者：郑昕[1,2] 孙羽 陈娇娇[1,2] 胡水明[1,2] Zheng Xin1,2, Sun Yu Robert1,2,Chen Jiao-Jiao1,2,Hu Shui-Ming1,2. 1.(Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China, Hefei 230026, China） 2. （ CAS Center for Excellence in Quantum Information and Quantum Physics, Hefei 230026, China)

机构地区：[1]中国科学技术大学合肥微尺度国家物质科学中心,合肥230026 [2]中国科学院量子信息与量子科技创新研究院,合肥230026

出　　处：《物理学报》2018年第16期165-182,共18页Acta Physica Sinica

基　　金：中国科学院先导(B)(批准号:XDB21010400;XDB21020100);国家自然科学基金(批准号:91736101;21688102;11304303;91436209);国家重点基础研究发展计划(批准号:2013CB834602)资助的课题~~

摘　　要：氦原子是最基本的多电子原子,其精密谱是十分理想的检验多电子量子电动力学计算的平台,同时也是利用原子能级结构测定精细结构常数α的理想体系,还能获得原子核结构信息.本文结合我们团队的工作,综述基于氦原子的少体原子精密光谱研究.其中,主要包括氦原子2~3P_J精细结构分裂,以及2~3S—2~3P跃迁频率测定等研究,并对相关工作的前景进行了展望.Precision measurement in few-electron atomic systems played an important role in testing fundamental physics and determination of the fundamental physical constants throughout the past few decades. Atomic helium, as the simplest multi-electron system, its energy levels can be calculated with a very high precision by means of ab-initio calculations,and can be accurately determined using precision spectroscopy. Test of quantum theories can be achieved by comparing theoretical predictions with experimental results. In case of any disagreement, it might imply that there are some undiscovered systematic effects, or might signal physics beyond the standard model. Particularly, the 2^3P energy level in atomic helium is considered as one of the best atomic systems for determining the fine-structure constant α. High precision helium spectroscopy can also be used for setting constraints on exotic spin-dependent interactions, and may provide an accurate determination of the helium nuclear charge radius. Comparison of results from electronic and muonic helium may provide a sensitive test of universality in electromagnetic interactions of leptons, and may help solve the socalled ＂proton size puzzle＂. In this paper, we summarize our recent progress on precision spectroscopy of atomic helium.By using transverse cooling and deflection, we are able to prepare a low-noise bright source of atoms in the metastable state 2^3S1. The initial state preparation is completed by optical pumping, followed by laser spectroscopy in the 2^3S–2^3P transition. The 2^3P0-2^3P2 and 2^3P1-2^3P2 fine-structure intervals are determined to be（31908130.98 ± 0.13） k Hz and（2291177.56 ± 0.19） k Hz, respectively. Compared with calculations including terms up to α7 m, the deviation for theα-sensitive interval 2^3P0-2^3P2 is only 0.22 k Hz, which paths way for further improvement of theoretical predictions and independent determination of α with a 2-ppb precision. The 2-3 S–2^3P transition frequency is determined with an accuracy of 1.

关 键 词：氦原子 精密光谱 精细结构常数 量子电动力学 

分 类 号：O413.2[理学—理论物理] O562[理学—物理]