Three-dimensional localization of the individual shallow NV center in diamond using a gold tip

This work presents a method for the three-dimensional localization of individual shallow NV center in diamond, leveraging the near-field quenching effect of a gold tip. Our experimental setup involves the use of an atomic force microscope to precisely move the gold tip close to the NV center, while simultaneously employing a home-made confocal microscope to monitor the fluorescence of the NV center. This approach allows for lateral super-resolution, achieving a full width at half maximum (FWHM) of 38.0 nm and a location uncertainty of 0.7 nm. Additionally, we show the potential of this method for determining the depth of the NV centers. We also attempt to determine the depth of the NV centers in combination with finite-difference time-domain (FDTD) simulations. Compared to other depth determination methods, this approach allows for simultaneous lateral and longitudinal localization of individual NV centers, and holds promise for facilitating manipulation of the local environment surrounding the NV center.