Jul 17 – 22, 2022
Royal Conservatory of Music, Toronto
America/Toronto timezone

An Optical Atomic Clock Based on a Highly Charged Ion

Jul 18, 2022, 5:00 PM
1h 30m
Hart House (Hart House)

Hart House

Hart House

7 Hart House Cir, Toronto, ON M5S 3H3
Poster presentation Precision measurement and tests of fundamental physics Poster session


Optical atomic clocks are the most precise and accurate measurement devices ever constructed, reaching fractional systematic uncertainties below one part in $10^{18}$ [1]. Their exceptional performance opens up a wide range of applications in fundamental science and technology. The extreme properties of highly charged ions (HCI) make them highly sensitive probes for tests of fundamental physical theories [2, 3]. Furthermore, these properties make them significantly less sensitive to some of the leading systematic perturbations that affect state-of-the-art optical clocks, making them exciting candidates for next-generation clocks [4, 2]. The technical challenges that hindered the development of such clocks have now all been overcome, starting with their extraction from a hot plasma and sympathetic cooling in a linear Paul trap [5], readout of their internal state via quantum logic spectroscopy [6], and finally the preparation of the HCI in the ground state of motion of the trap [7], which allows levels of measurement accuracy to be reached that were previously limited to singly-charged and neutral atoms. Here, we present the first operation of an atomic clock based on an HCI (Ar$^{13+}$ in our case) and a full evaluation of systematic frequency shifts [8]. The achieved uncertainty is almost eight orders of magnitude lower than any previous frequency measurements using HCI. Measurements of some key atomic parameters confirm the theoretical predictions of the favorable properties of HCIs for use in clocks. The comparison to the $^{171}$Yb$^+$ E3 optical clock [9] places the frequency of this transition among the most accurately measured of all time. Furthermore, by comparing the isotope shift between $^{36}$Ar$^{13+}$ and $^{40}$Ar$^{13+}$ to improved atomic structure calculations, we were able for the first time to resolve the largely unexplored QED nuclear recoil effects. Finally, prospects for 5th force tests based on isotope shift spectroscopy of Ca$^+$/Ca$^{14+}$ isotopes and the high-sensitivity search for a variation of the fine-structure constant using HCI will be presented. This demonstrates the suitability of HCI as references for high-accuracy optical clocks and to probe for physics beyond the standard model.

[1] Brewer, S. M. et al., Phys. Rev. Lett. 123, 033201 (2019).
[2] Kozlov, M. G. et al., Rev. Mod. Phys. 90, 045005 (2018).
[3] Safronova, M. S. et al., Rev. Mod. Phys. 90, 025008 (2018).
[4] Schiller, S., Phys. Rev. Lett. 98, 180801 (2007).
[5] Schmöger, L. et al., Science 347, 1233–1236 (2015).
[6] Micke, P. et al., Nature 578, 60–65 (2020).
[7] King, S. A. et al., Phys. Rev. X 11, 041049 (2021).
[8] King, S. A. et al., http://arxiv.org/abs/2205.13053.
[9] Lange, R. et al., Phys. Rev. Lett. 126, 011102 (2021).

Presenter name Piet O. Schmidt
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Primary authors

Dr Steven King (Physikalisch-Technische Bundesanstalt) Mr Lukas Spieß (Physikalisch-Technische Bundesanstalt) Dr Peter Micke (Physikalisch-Technische Bundesanstalt) Mr Alexander Wilzewski (Physikalisch-Technische Bundesanstalt) Dr Tobias Leopold (Physikalisch-Technische Bundesanstalt) Dr Erik Benkler (Physikalisch-Technische Bundesanstalt) Dr Richard Lange (Physikalisch-Technische Bundesanstalt) Dr Nils Huntemann (Physikalisch-Technische Bundesanstalt) Prof. Andrey Surzhykov (Physikalisch-Technische Bundesanstalt) Dr Vladimir Yerokhin (Physikalisch-Technische Bundesanstalt) Prof. José R. Crespo López-Urrutia (Max-Planck-Institut für Kernphysik) Prof. Piet O. Schmidt (Physikalisch-Technische Bundesanstalt)

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