PHYSICS:
Logical Spectroscopy
Ekkehard Peik
Laser cooling and spectroscopy is a powerful method for obtaining precise information about the electronic transitions in atoms. Unfortunately, many atoms lack the characteristics needed to be candidates for precision laser spectroscopy. In his Perspective, Peik discusses a method reported by Schmidt et al. in this issue in which the tools of quantum information processing are used to open up a wider range of atoms for study. A "logic ion" with well-known properties is stored in an electric trap with a second "spectroscopy ion" that is to be studied. By allowing the two ions to interact in the trap, the internal state of the spectroscopy ion can be mapped onto the logic ion and read out via laser fluorescence. The technique should make it possible to perform high-precision laser spectroscopy on a new set of atoms and use them for the next generation of atomic clocks.
The author is in the Time and Frequency Department, Physikalisch-Technische Bundesanstalt, 38116 Braunschweig, Germany. E-mail: ekkehard.peik{at}ptb.de
