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arXiv · 1312.3419

A strontium lattice clock with $3 \times 10^{-17}$ inaccuracy and its frequency

Stephan Falke·Nathan Lemke·Christian Grebing·Burghard Lipphardt·Stefan Weyers·Vladislav Gerginov·Nils Huntemann·Christian Hagemann·Ali Al-Masoudi·Sebastian Häfner·Stefan Vogt·Uwe Sterr·Christian Lisdat
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Abstract

We have measured the absolute frequency of the optical lattice clock based on $^{87}$Sr at PTB with an uncertainty of $3.9\times 10^{-16}$ using two caesium fountain clocks. This is close to the accuracy of today's best realizations of the SI second. The absolute frequency of the 5s$^2$ $^1$S$_0$-5s5p $^3$P$_0$ transition in $^{87}$Sr is 429,228,004,229,873.13(17) Hz. Our result is in excellent agreement with recent measurements performed in different laboratories worldwide. We improved the total systematic uncertainty of our Sr frequency standard by a factor of five and reach $3\times 10^{-17}$, opening new prospects for frequency ratio measurements between optical clocks for fundamental research, geodesy, or optical clock evaluation.

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Stephan Falke, Nathan Lemke, Christian Grebing, Burghard Lipphardt, Stefan Weyers, Vladislav Gerginov, Nils Huntemann, Christian Hagemann, Ali Al-Masoudi, Sebastian Häfner, Stefan Vogt, Uwe Sterr, Christian Lisdat. 2013-12-12. A strontium lattice clock with $3 \times 10^{-17}$ inaccuracy and its frequency. https://doi.org/10.1088/1367-2630/16/7/073023

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