发表机构
Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften; Universität Innsbruck, Institut für Experimentalphysik; Alpine Quantum Technologies GmbH; Singapore University of Technology and Design; Qatar Center for Quantum Computing, College of Science and Engineering, Hamad Bin Khalifa University（奥地利科学院量子光学与量子信息研究所; 因斯布鲁克大学实验物理研究所; 阿尔卑斯量子技术有限公司; 新加坡科技设计大学; 哈马德·本·哈利法大学科学与工程学院卡塔尔量子计算中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过GNSS链路将因斯布鲁克实验室的$^{40}$Ca$^{+}$钟与PTB协调世界时比较，测得钟跃迁频率为411 042 129 776 401.2 Hz，不确定度1.5×10$^{-15}$，并重新评估了朗德g因子。
AI 中文摘要
我们报告了相对于SI秒的$4s$ $^{2}S_{1/2}\leftrightarrow 3d$ $^{2}D_{5/2}$ $^{40}$Ca$^{+}$钟跃迁的绝对频率测量。为进行此测量，我们安装并表征了因斯布鲁克实验室与位于布伦瑞克的德国联邦物理技术研究院（PTB）实现协调世界时的时钟之间的链路，该链路使用全球导航卫星系统GNSS。我们与PTB时钟的比较采用精密单点定位技术完成。在评估系统频移后，测得的跃迁频率为411 042 129 776 401.2$\pm$0.6 Hz，分数不确定度为1.5 $\times$ 10$^{-15}$。时钟测量的稳定性还通过比较两个共享我们研究所时钟激光源的钙离子钟实验得到证实。此外，在仔细评估阱驱动感应的交流磁场后，我们估计了$D_{5/2}$子能级上的交流塞曼频移，并重新评估了$3d$ $^{2}D_{5/2}$能级的朗德g因子为g$_{5/2}= 1.200329(1)$。
英文摘要
We report the absolute frequency measurement of the $4s$ $ ^{2}S_{1/2}\leftrightarrow 3d$ $^{2}D_{5/2}$ $^{40}$Ca$^{+}$ clock transition with respect to the SI second. To perform this measurement, a link between our laboratory in Innsbruck and the clocks realizing the Coordinated Universal Time at the Physikalisch-Technische Bundesanstalt (PTB) in Braunschweig was installed and characterized using the Global Navigation Satellite System GNSS. The comparison between our clock and the ones at PTB was done using the Precise Point Positioning technique. After the evaluation of the systematic shifts, the measured transition frequency is 411 042 129 776 401.2$\pm$0.6 Hz with a fractional uncertainty of 1.5 $\times$ 10$^{-15}$. The stability of the clock measurements was also corroborated by comparing two different calcium ion clock experiments, which share the clock laser source at our institute. Furthermore, after careful evaluation of the trap-drive induced ac magnetic fields, we estimate ac Zeeman shifts on the $D_{5/2}$ sublevels and reevaluate the Landé g-factor of the $3d$ $^{2}D_{5/2}$ level to be g$_{5/2}= 1.200329(1)$.
Comments10 pages, 4 figures
