极紫外波段的少电子原子精密光谱测量  

Precision spectroscopic measurements of few-electron atomic systems in extreme ultraviolet region

作　　者：肖峥嵘 张恒之 华林强 唐丽艳 柳晓军 Xiao Zheng-Rong;Zhang Heng-Zhi;Hua Lin-Qiang;Tang Li-Yan;Liu Xiao-Jun(State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics,Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院精密测量科学与技术创新研究院,波谱与原子分子物理国家重点实验室,武汉430071 [2]中国科学院大学,北京100049

出　　处：《物理学报》2024年第20期100-111,共12页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12121004,U21A20435,12393823,92265206,12174402,12393821);中国科学院基础与交叉前沿科研先导专项(B类先导专项)(批准号:0920000);中国科学院稳定支持基础研究领域青年团队计划(批准号:YSBR-055)资助的课题.

摘　　要：基于少电子原子体系的精密光谱测量为“质子半径之谜”、量子电动力学高精度检验等重大科学问题的解决带来曙光,因此备受关注.然而,少电子体系许多重要的跃迁谱线位于真空/极紫外波段,缺少合适的窄线宽光源是阻碍其测量精度进一步提升的主要原因之一.近年来,基于稀有气体高次谐波过程产生的极紫外窄线宽相干光源为精密测量这些跃迁谱线带来了新的机遇.最新研究表明,极紫外光梳的最短波长可至12 nm,最高功率可至mW量级,线宽可至0.3 MHz;而极紫外波段的拉姆齐光梳亦可以实现kHz量级的光谱精度,且其工作波长有潜力覆盖整个极紫外波段.本文重点介绍少电子原子极紫外波段精密光谱测量相关技术方法与研究进展.首先简要介绍基于少电子原子体系精密光谱测量的科学意义;随后介绍极紫外波段少电子原子体系精密光谱测量方法,即基于极紫外光梳的直接频率梳光谱方法和极紫外波段的拉姆齐频率梳光谱方法;然后介绍利用这些方法开展少电子原子体系精密光谱实验测量以及相关精密谱理论计算方面的研究进展,以及这些方法在其他相关研究中面临的重要机遇;最后给出未来工作展望.Precision spectroscopic measurements on the few-electron atomic systems have attracted much attention because they shed light on important topics such as the“proton radius puzzle”and testing quantum electrodynamics(QED).However,many important transitions of few-electron atomic systems are located in the vacuum/extreme ultraviolet region.Lack of a suitable narrow linewidth light source is one of the main reasons that hinder the further improvement of the spectral resolution.Recently,narrow linewidth extreme ultraviolet(XUV)light sources based on high harmonic processes in rare gases have opened up new opportunities for precision measurements of these transitions.The recently implemented XUV comb has a shortest wavelength of about 12 nm,a maximum power of milliwatts,and a linewidth of about 0.3 MHz,making it an ideal tool for precision measurements in the XUV band.At the same time,the Ramsey comb in the XUV band can achieve a spectral resolution of the kHz range,and may operate throughout the entire XUV band.With these useful tools,direct frequency spectroscopy and Ramsey comb spectroscopy in the XUV region are developed,and precision spectroscopic measurements of few-electron atomic systems with these methods are becoming a hot topic in cutting-edge science.In this paper,we provide an overview of the current status and the progress of relevant researches,both experimentally and theoretically,and discuss the opportunities for relevant important transitions in the extreme ultraviolet band.

关 键 词：少电子原子 精密光谱测量 极紫外光梳 拉姆齐光梳 量子电动力学 

分 类 号：O562.3[理学—原子与分子物理]