$^{171}$Yb$^+$ optical clock with $2.2\times 10^{-18}$ systematic uncertainty and absolute frequency measurements

Alexandra Tofful; Charles F. A. Baynham; E. Anne Curtis; Adam O. Parsons; Billy I. Robertson; Marco Schioppo; Jacob Tunesi; Helen S. Margolis; Richard J. Hendricks; Josh Whale; Richard C. Thompson; Rachel M. Godun

doi:10.1088/1681-7575/ad53cd

arXiv · 2403.14423

$^{171}$Yb$^+$ optical clock with $2.2\times 10^{-18}$ systematic uncertainty and absolute frequency measurements

Alexandra Tofful·Charles F. A. Baynham·E. Anne Curtis·Adam O. Parsons·Billy I. Robertson·Marco Schioppo·Jacob Tunesi·Helen S. Margolis·Richard J. Hendricks·Josh Whale·Richard C. Thompson·Rachel M. Godun

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Abstract

A full evaluation of the uncertainty budget for the ytterbium ion optical clock at the National Physical Laboratory (NPL) was performed on the electric octupole (E3) $^2\mathrm{S}_{1/2}\,\rightarrow\, ^2\mathrm{F}_{7/2}$ transition. The total systematic frequency shift was measured with a fractional standard systematic uncertainty of $2.2\times 10^{-18}$. Furthermore, the absolute frequency of the E3 transition of the $^{171}$Yb$^+$ ion was measured between 2019 and 2023 via a link to International Atomic Time (TAI) and against the local caesium fountain NPL-CsF2. The absolute frequencies were measured with fractional standard uncertainties between $3.7 \times 10^{-16}$ and $1.1 \times 10^{-15}$, and all were in agreement with the 2021 BIPM recommended frequency.

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Alexandra Tofful, Charles F. A. Baynham, E. Anne Curtis, Adam O. Parsons, Billy I. Robertson, Marco Schioppo, Jacob Tunesi, Helen S. Margolis, Richard J. Hendricks, Josh Whale, Richard C. Thompson, Rachel M. Godun. 2024-03-21. $^{171}$Yb$^+$ optical clock with $2.2\times 10^{-18}$ systematic uncertainty and absolute frequency measurements. https://doi.org/10.1088/1681-7575/ad53cd

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