Superior atomic coherence time controlled by crystal phase transition and optical dressing

Abstract

We compare the atomic coherence time of doped ion crystals, i.e., BiPO4: Eu3+, YPO4: Eu3+, YPO4: Pr3+, and Y2SiO5: Pr3 + crystals. Such atomic coherence time is controlled by crystal field splitting (CF-splitting) and optical (photon and phonon) dressing. Compared with the other doped ion crystals, BiPO4: Eu3+ exhibits the longest coherence time. By controlling thermal phonon, phase-transition phonon, broadband or narrowband excitation, and fluorescence (FL) or spontaneous four-wave-mixing ratio (S-FWM), a superior atomic coherence time of up to 10 ± 0.6 ms is achieved in the pure hexagonal (0.5:1) phase of BiPO4: Eu3+. Furthermore, the relationship between TAT-splitting and spectral Autler–Townes (SAT)-splitting was investigated. This superior atomic coherence time has potential applications in quantum memory devices.