Darmstadt 2008 – scientific programme
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A: Fachverband Atomphysik
A 30: Precision spectroscopy III
A 30.3: Talk
Friday, March 14, 2008, 14:30–14:45, 3C
Absolute frequency measurements on Mg+ cooling transitions — •Valentin Batteiger1, Maximilian Herrmann1, Sebastian Knünz1, Birgitta Bernhardt1, Feng Zhu2, Hans Schüssler2, Thomas Udem1, and Theodor W. Hänsch1 — 1Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching — 2Texas A&M University, College Station, Texas 77843
We present isotopically resolved absolute frequency measurements of both fine structure components of the 3s-3p transition in single, trapped magnesium ions. The transitions are observed in the limit of unresolved sidebands, which would lead to strongly asymmetric line shapes due to cooling and heating if only one laser were swept over the resonance. A novel spectroscopy scheme based on sympathetic cooling and spatially resolved detection allows to observe symmetric lines. The measurements contribute to astronomical searches for drifts of the fine structure constant in quasar absorption spectra and improve the accuracy over previous measurements by two orders of magnitude.