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Precision spectroscopy with single ions

Spectroscopy
Spectroscopy is a powerful tool that can identify chemical species used in a wide range of settings. Usually, the samples are formed of ensembles, and this can limit the resolution with which the different species can be detected or identified. Chou et al. demonstrate an optical frequency comb technique with a single pair of trapped ions, Ca+ and CaH+, to obtain the rotational spectrum of a single trapped ion, CaH+. With the ions isolated and the ensemble interactions removed, the rotational structure of the trapped molecular ion can then be obtained with high precision. As the trapping and manipulation process is general, this technique could be applied to a number of chemical species for specific purposes.

Science , this issue p. [1458][1]

 [1]: /lookup/doi/10.1126/science.aba3628