Charge StateTransition of Spectrally Stabilized Tin-VacancyCenters in Diamond

Solid-state quantum emitters are important platforms for quantum information processing. The fabrication of the emitters with stable photon frequency and narrow line width is a fundamental issue, and it is essential to understand optical conditions under which the emitter keeps a bright charge state or transitions to a dark state. For these purposes, in this study, we investigate the spectral stability and charge state transition of tin-vacancy (SnV) centers in diamond. The photoluminescence excitation spectra of multiple SnV centers are basically stable over time with nearly transform-limited line widths under resonant excitation, while simultaneous irradiation of resonant and nonresonant lasers makes spectra from the SnV centers unstable. We find that the instability occurs due to the charge state transition to a dark state. The charge state transition rates are quantitatively investigated depending on the laser powers. Lastly, with first-principles calculations, we model the charge state transition of the SnV center under laser irradiation.