- Accepted Paper
Precision spectroscopy of a trapped ion using a bath of ultracold atoms
Phys. Rev. Lett. - Accepted 28 October, 2026
DOI: https://doi.org/10.1103/fq33-db1l
Phys. Rev. Lett. - Accepted 28 October, 2026
DOI: https://doi.org/10.1103/fq33-db1l
We perform laser spectroscopy of a trapped ion that is not directly laser cooled. An ultracold atomic bath continuously cools the internal degrees of freedom of the ion to its hyperfine ground state via spin-exchange collisions while a co-trapped Yb ion sympathetically cools the external degrees of freedom. Successful laser excitation is detected via state-selective charge transfer following a collision with an atom and subsequent ion loss. As a demonstration of this spectroscopic technique, we probe the transition at 329~nm in Yb and measure the magnetic and electric hyperfine interaction constants for the state to be ~MHz and ~MHz, respectively. Our results are in agreement with a previous measurement obtained in a hollow-cathode discharge experiment but are a factor of 6–9 more precise. The techniques demonstrated in this work may be extended to perform precision spectroscopy on ions with complex level structures with applications in fundamental physics.
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