Scanning photocurrent imaging resolution of single NV center in diamond

We investigated the spatial resolution of scanning photocurrent microscopy (SPhM) for imaging single nitrogen-vacancy (NV) centers in diamond in detail and compared it with that of confocal laser scanning microscopy (CLSM). While CLSM suffers from degraded spatial resolution due to fluorescence saturation, SPhM maintains a high spatial resolution despite the high-power laser excitation required. Numerical simulations of SPhM and CLSM images showed good agreement with experimental data and further indicated that SPhM achieves superior spatial resolution. Additionally, the signal-to-noise ratio of the photoelectrically detected magnetic resonance spectrum is comparable to that of the optically detected magnetic resonance spectrum in our home-made spectrometers. These findings suggest that SPhM can enhance the performance of NV-based quantum sensors.