Ultrafast Conversion of Two Charge States of Nitrogen-Vacancy Centers in Diamond via Two-Photon Excitation.

Ultrafast conversion dynamics between the NV⁰ and NV^- charge states in diamond is crucial for spin-state manipulation and readout. However, the underlying mechanism of the conversion, including the effective excitation wavelength, the time scales of the conversion, and the influencing factors, is still unclear. Here, we proposed a method to probe the ultrafast conversion of the two charge states via two-photon excitation with femtosecond laser pulses separated by 12.5 ns. We found that the highest conversion efficiency occurs at the excitation wavelength of around 532 nm, and the efficiency increases with temperature as well. The conversion time from NV⁰ to NV^- is obtained to be around 75 ps at 300 K. These findings advance the understanding of NV center charge-state dynamics and provide insights for high-speed spin readout in quantum information applications.

Duke Scholars

Author Changcheng Zheng DKU Faculty