Abstract:
The nitrogen-vacancy (NV) center in nanodiamonds has emerged as an excellent platform in quantum
technologies due to its applications in spin manipulation and nanoscale sensing. However, their use is limited
by the unavoidable charge-state conversion under optical pumping. In this study, we investigate the control
of charge-state conversion in NV centers using an engineered photonic environment and thus change the
available local density of optical states (LDOS). The spectral- and pump-dependent decay rate measurements
are performed to study the redistribution of emission rates due to the change in LDOS and their effect on
charge-state conversion. We have achieved an 8% enhancement of emission rate at the zero phonon line which
is accompanied with a 10% suppression in the phonon sideband emission rate in the low-pump-power regime.
In the high-pump-power regime, the charge-state conversion becomes inevitable and leads to the deterioration of
LDOS-induced modification in the NV center emission lifetimes. The results are useful for efficient NV center
spin readout and charge-state depletion microscopy utilizing reversible charge-state conversion.
