title: Frequency metrology on single trapped ions in the weak binding limit: the 3s(1/2)-3p(3/2) transition in 24Mg+.
abstract: We demonstrate a method for precision spectroscopy on trapped ions in the limit of unresolved motional sidebands. By sympathetic cooling of a chain of crystallized ions, we suppress adverse temperature variations induced by the spectroscopy laser that usually lead to a distorted line profile and obtain a Voigt profile with negligible distortions. We applied the method to measure the absolute frequency of the astrophysically relevant D2 transition in single 24Mg+ ions and find 1 072 082 934.33(16) MHz, a nearly 400-fold improvement over previous results. Further, we find the excited state lifetime to be 3.84(10) ns.
authors.affiliation: Max Planck Institut für Quantenoptik, Hans Kopfermann Strasse 1, 85748 Garching, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Herrmann
authors.forename: V
authors.initials: V
authors.lastname: Batteiger
authors.forename: S
authors.initials: S
authors.lastname: Knünz
authors.forename: G
authors.initials: G
authors.lastname: Saathoff
authors.forename: Th
authors.initials: T
authors.lastname: Udem
authors.forename: T W
authors.initials: TW
authors.lastname: Hänsch