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arXiv · 1403.6285

Direct comparison of optical lattice clocks with an intercontinental baseline of 9 000 km

H. Hachisu·M. Fujieda·S. Nagano·T. Gotoh·A. Nogami·T. Ido·St. Falke·N. Huntemann·C. Grebing·B. Lipphardt·Ch. Lisdat·D. Piester
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Abstract

We have demonstrated a direct frequency comparison between two $^{87}{\rm Sr}$ lattice clocks operated in intercontinentally separated laboratories in real time. Two-way satellite time and frequency transfer technique based on the carrier phase was employed for a direct comparison with a baseline of 9 000 km between Japan and Germany. A clock comparison was achieved for 83 640 s resulting in a fractional difference of $(1.1\pm1.6) \times 10^{-15}$, where the statistical part is the biggest contribution to the uncertainty. This measurement directly confirms the agreement of the two optical clocks on an intercontinental scale.

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H. Hachisu, M. Fujieda, S. Nagano, T. Gotoh, A. Nogami, T. Ido, St. Falke, N. Huntemann, C. Grebing, B. Lipphardt, Ch. Lisdat, D. Piester. 2014-03-25. Direct comparison of optical lattice clocks with an intercontinental baseline of 9 000 km. https://doi.org/10.1364/ol.39.004072

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