Part of the dressed state picture relevant for the three-photon resonance condition, giving rise to the coherent dark state
Figures are generally photos, graphs and static images that would be represented in traditional pdf publications.
Figure 2. Part of the dressed state picture relevant for the three-photon resonance condition, giving rise to the coherent dark state. The straight lines stand for laser couplings and the wavy lines for radiative decay (see the text for details).
A stimulated Raman adiabatic passage (STIRAP)-like scheme is proposed to exploit a three-photon resonance taking place in alkaline-earth-metal ions. This scheme is designed for state transfer between the two fine structure components of the metastable D-state which are two excited states that can serve as optical or THz qubit. The advantage of a coherent three-photon process compared to a two-photon STIRAP lies in the possibility of exact cancellation of the first-order Doppler shift which opens the way for an application to a sample composed of many ions. The transfer efficiency and its dependence with experimental parameters are analysed by numerical simulations. This efficiency is shown to reach a fidelity as high as (1–8 × 10−5) with realistic parameters. The scheme is also extended to the synthesis of a linear combination of three stable or metastable states.