Others Frequency Ratio of 199Hg and 87Sr Optical Lattice Clocks beyond the SI Limit

Yamanaka Kazuhiro  ,  Ohmae Noriaki  ,  Ushijima Ichiro  ,  Takamoto Masao  ,  Katori Hidetoshi

114 ( 23 ) 2015-06-10 , American Physical Society , Quantum Metrology Laboratory, RIKEN , Innovative Space-Time Project, ERATO, JST , Department of Applied Physics, Graduate School of Engineering, The University of Tokyo
ISSN:1079-7114 (online)
UTokyo Research掲載「水銀・ストロンチウム光格子時計の高精度直接比較に成功」 URI: http://www.u-tokyo.ac.jp/ja/utokyo-research/research-news/highly-precise-comparison-of-mercury-and-strontium-optical-lattice-clocks.html
UTokyo Research "Highly-precise comparison of mercury and strontium optical lattice clocks" URI: http://www.u-tokyo.ac.jp/en/utokyo-research/research-news/highly-precise-comparison-of-mercury-and-strontium-optical-lattice-clocks.html
We report on a frequency ratio measurement of a Hg199-based optical lattice clock referencing a Sr87-based clock. Evaluations of lattice light shift, including atomic-motion-dependent shift, enable us to achieve a total systematic uncertainty of 7.2×10−17 for the Hg clock. The frequency ratio is measured to be νHg/νSr=2.629 314 209 898 909 60(22) with a fractional uncertainty of 8.4×10−17, which is smaller than the uncertainty of the realization of the International System of Units (SI) second, i.e., the SI limit.


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