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arXiv · 1503.07941

Frequency Ratio of ${}^{199}$Hg and ${}^{87}$Sr Optical Lattice Clocks beyond the SI Limit

Kazuhiro Yamanaka·Noriaki Ohmae·Ichiro Ushijima·Masao Takamoto·Hidetoshi Katori
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Abstract

We report on a frequency ratio measurement of a ${}^{199}$Hg-based optical lattice clock referencing a ${}^{87}$Sr-based clock. Evaluations of lattice light shift, including atomic-motion-dependent shift, enable us to achieve a total systematic uncertainty of $7.2 \times 10^{-17}$ for the Hg clock. The frequency ratio is measured to be $\nu_{\rm Hg}/\nu_{\rm Sr}=2.629\, 314\, 209\, 898\, 909\, 60(22)$ with a fractional uncertainty of $8.4 \times 10^{-17}$, which is smaller than the uncertainty of the realization of the SI second, i.e., the SI limit.

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Kazuhiro Yamanaka, Noriaki Ohmae, Ichiro Ushijima, Masao Takamoto, Hidetoshi Katori. 2015-03-27. Frequency Ratio of ${}^{199}$Hg and ${}^{87}$Sr Optical Lattice Clocks beyond the SI Limit. https://arxiv.org/abs/1503.07941

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