Frequency ratio of an ${}^{115}$In${}^{+}$ ion clock and a ${}^{87}$Sr optical lattice clock

Abstract

We report on the first frequency ratio measurement of an ${}^{115}$In+ single ion clock and a ${}^{87}$Sr optical lattice clock. A hydrogen maser serves as a reference oscillator to measure the ratio by independent optical combs. Over more than 90 000 seconds of measurement time, the frequency ratio $f_{\mathrm{I}{\mathrm{n}}^{+}}/f_{\mathrm{Sr}}$ is determined to be 2.952 748 749 874 863 4(21) with relative uncertainty of $7.0\times 10^{-16}$. The measurement creates a new connection in the network of frequency ratios of optical clocks.

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• An ${}^{27}$Al${}^{+}$ quantum-logic clock with systematic uncertainty below $10^{-18}$
• Frequency ratio of two optical clock transitions in ${}^{171}$Yb${}^{+}$ and constraints on the time-variation of fundamental constants
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Cited by in corpus (5)

• ${}^{115}$In${}^{+}$-${}^{172}$Yb${}^{+}$ Coulomb crystal clock with $2.5\times 10^{-18}$ systematic uncertainty
• Prospects of a Pb${}^{2+}$ ion clock
• An ultra-stable cryogenic sapphire cavity laser with an instability of $1.9\times 10^{-16}$ based on a low vibration level cryostat
• Phase-stabilized UV light at 267 nm through twofold second harmonic generation
• International Optical Clock Comparison Using the European Optical Fiber Network