发表机构
Vrije Universiteit Amsterdam; Sorbonne Université; Physikalisch-Technische Bundesanstalt; Leibniz Universität Hannover（阿姆斯特丹自由大学; 索邦大学; 德国联邦物理技术研究院; 汉诺威莱布尼茨大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出新型量子逻辑光谱学方法，数值验证其可实现单电离氦1S-2S跃迁的10 kHz级精密光谱，可用于改进量子电动力学测试等，也适用于拉曼-迪克区外其他离子的XUV光谱学。
AI 中文摘要
极紫外（XUV）光谱学是精密物理学的重要新方向，潜在应用范围从基本常数计量学到超出标准模型的物理测试。然而，在XUV波段应用量子控制方法进行精密光谱学仍是未解决的挑战。本文提出一种新型量子逻辑（QL）光谱学方法，用于弱XUV跃迁的精密光谱学，并数值验证其对单电离氦（He⁺）中40.81 eV的1S-2S跃迁的可行性。我们提出的方案基于单个He⁺离子与Be⁺离子共囚禁于保罗阱，He⁺的激发采用经高次谐波产生（HHG）上转换至XUV的频率梳（FC）激光脉冲对。我们研究一种非破坏性QL方案以检测1S-2S激发，并将其性能与基于态选择电离的破坏性读出方案对比。我们对XUV光的相位相干性进行建模，并在HHG前用光腔过滤FC脉冲。我们对囚禁离子在拉曼-迪克（Lamb-Dicke）区外的运动激发动力学进行建模，数值验证了我们在文献[Grundeman]中提出的方案，该方案通过同步离子的周期运动与两个激发脉冲间的时间延迟，可抵消一阶多普勒展宽和反冲位移。我们表明，在10 kHz量级实现He⁺中1S-2S跃迁的精密光谱学是可行的，这可用于改进量子电动力学（QED）测试、独立于氢测量的里德伯常数R∞测量，或改进α粒子与氦核电荷半径的测定。所提方法也可应用于拉曼-迪克区外其他离子的XUV光谱学。
英文摘要
Extreme-ultraviolet (XUV) spectroscopy represents an important new direction in precision physics, with potential applications ranging from the metrology of fundamental constants to tests of physics beyond the Standard Model. However, the application of quantum control methods for precision spectroscopy remains an open challenge in the XUV range. Here we present a novel quantum logic (QL) spectroscopy method for precision spectroscopy of weak XUV transitions, and numerically validate its feasibility for the $1S-2S$ transition at 40.81\,eV in singly-ionized helium (He$^{+}$). We propose a scheme based on a single He$^{+}$ ion co-trapped with a Be$^{+}$ ion in a Paul trap, and He$^{+}$ excitation with pairs of frequency-comb (FC) laser pulses upconverted to the XUV via High-Harmonic Generation (HHG). We investigate a nondestructive QL scheme to detect $1S-2S$ excitation, and compare its performance with a destructive readout based on state-selective ionization. Phase coherence of the XUV light is modelled and an optical cavity is used to filter the FC pulses prior to HHG. We model the motional excitation dynamics of trapped ions outside the Lamb-Dicke regime, and numerically validate a scheme we proposed in \cite{Grundeman} to cancel the first-order Doppler broadening and the recoil shift by synchronizing the ion's secular period with the time delay between the two excitation pulses. We show that precision spectroscopy of the $1S-2S$ transition in He$^{+}$ at the 10 kHz level is feasible, for improved tests of quantum electrodynamics (QED), a measurement of the Rydberg constant $R_{\infty}$ independent of hydrogen measurements, or an improved determination of the alpha particle and helion charge radii. The proposed method may also be applied to XUV spectroscopy of other ions outside the Lamb-Dicke regime.
Comments26 pages, 19 figures
