LOA PhD Seminar: Amélie Chies (QUANTUM): Characterization of ultrafast charge-state switching dynamics in NV centers of diamond

Characterization of ultrafast charge-state switching dynamics in NV centers of diamond

The negatively charged nitrogen-vacancy (NV–) center in diamond has been established as a promising platform for quantum sensing due to its spin-dependent photoluminescence at room temperature. However, improving the sensitivity of these techniques requires a deeper understanding of the processes driving charge state conversion between NV– and the neutral charge state (NV0). This study investigates the ultrafast dynamics of photoluminescence and infrared (IR) absorption, and their dependence on IR fluence. Using pump-probe and time-resolved photoluminescence techniques with joint excitation at 515 nm and 1030 nm, and a temporal resolution on the order of hundreds of femtoseconds, we observe a significant IR-induced enhancement of the NV– population. Our results also reveal the presence of an IR power threshold reversing the direction of the charge state conversion dynamics. Additionally, the time-resolved photoluminescence method proves to be a promising approach for investigating the photophysics of NV centers, and these findings open new pathways for optimizing high-precision quantum sensing applications.