基于可搬运光钟的低于5×10^-18不确定度的跨物种钟比对
Interspecies clock comparison below $5 \times 10^{-18}$ uncertainty with a transportable clock
浏览论文内容
中文总结 AI 辅助
该研究通过可搬运光钟与固定单离子钟开展近2年的跨物种钟比对，测得光频比不确定度达4.3×10^-18，提升了3倍以上，验证了可搬运钟用于计时测地及跨机构钟比对的可行性。
中文摘要 AI 辅助
我们报告了171Yb+的²S₁/₂(F=0)-²F₇/₂(F=3)电八极（E3）跃迁与87Sr的¹S₀-³P₀跃迁的光频比测量结果：ν_Yb⁺/ν_Sr = 1.4959916185449005881(65)。该结果的分数不确定度达4.3×10^-18，较此前最优结果提升了3倍以上，且满足国际单位制（SI）秒重新定义路线图规定的跨物种钟比对要求。本次比对在可搬运光晶格钟与固定单离子钟之间开展，历时近2年，期间可搬运钟曾间歇性在校外运行。研究人员分4个独立实验周期对该频率比进行了可重复测量，各周期结果在统计不确定度范围内一致。上述结果验证了可搬运钟可实现10^-18量级的稳定运行，可用于测地学中的计时研究，也可作为跨机构钟比对的传递标准，适用于无光纤链路的场景。
英文摘要
We report a measurement of the optical frequency ratio between the $^2\mathrm{S}_{1/2}(F=0)$--${^2\mathrm{F}_{7/2}(F=3)}$ electric-octupole (E3) transition of $^{171}$Yb$^{+}$ and the $^1\mathrm{S}_0$--${^3\mathrm{P}_0}$ transition of $^{87}$Sr, $ν_{\mathrm{Yb}^{+}}/ν_\mathrm{Sr} = 1.495\,991\,618\,544\,900\,588\,1(65)$. Reaching a fractional uncertainty of $4.3 \times 10^{-18}$, this result improves upon the previous best by more than a factor of three and is among the few that meet the requirements for interspecies clock comparisons specified by the roadmap towards the redefinition of the SI second. The comparison is between a transportable optical lattice clock and a stationary single-ion clock. It spans a period of nearly two years, during which the transportable clock was intermittently operated off-campus. The ratio was reproducibly measured during four separate campaigns, which are consistent within their statistical uncertainties. The results demonstrate reproducible $10^{-18}$ level operation of the transportable clock and thus validate its application for chronometric geodesy and as a transfer standard for inter-institute clock comparisons, e.g., in the absence of optical fiber links.
