Repumping MediatedEmission Manipulation of Single-PhotonEmitter by Optical Coexcitation

Single-photon emitters (SPEs) are essential for the advancement of quantum computing and information processing but face significant challenges. Current defect-based SPEs experience spectral diffusion and reduced photoluminescence efficiency due to electrons transitioning through dark states without photon emission. Additionally, these SPEs are highly sensitive to environmental fluctuations, affecting qubit stability. This study introduces a convenient optical coexcitation scheme to mitigate these issues in the SPE hosted in hexagonal boron nitride. This scheme repumps electrons from the metastable state to an intermediate state, enhancing their transition back to the excited state. This process significantly improves zero-phonon line emission while reducing phonon sideband intensity. Moreover, the coexcitation scheme increases tolerance to magnetic field and temperature variations. Long-duration photon count measurements demonstrate improved robustness of the SPE under this scheme. Overall, this research presents a simple strategy that enhances photon emission and stabilizes SPE performance against environmental disturbances, marking a notable advancement in quantum computing.