All Abstracts | Poster Abstracts | Talk Abstracts

Schrödinger cat state spectroscopy with trapped ions

Christian Roos, Institute for Quantum Optics and Quantum Information

(Session 8 : Saturday from 8:30 - 9:15)

Abstract. Trapped and laser-cooled ions have excellent properties for high-precision spectroscopy. By quantum logic spectroscopy, ions whose internal state cannot be detected easily can be read out via a second ion species trapped together with the spectroscopy ion. I will discuss the use of geometric phases for a particular type of quantum logic spectroscopy that can be used to detect the absorption or emission of single photons with high detection efficiency. By preparing a Schrödinger cat state of a two-ion crystal where the ions's motion is entangled with the internal states of the logic ion, a photon scattered by the spectroscopy ion manifests itself by a geometric phase that can be subsequently read out via the logic ion. This measurement scheme is applied to a mixed ion crystal of two calcium isotopes.