Nitrogen-vacancy centers with high intrinsic effective fields as probes for electric noise

Characterizing electric field noise in diamond is crucial for utilizing nitrogen-vacancy (NV) centers as probes and qubits. However, NV centers under axial magnetic fields are sensitive to magnetic fields and thus are limited in their ability to characterize electric fields directly. In this study, we engineered NV centers exhibiting strong intrinsic effective electric fields through ion implantation into CVD-grown diamond. We selected seven NV centers with splittings in the range of 18–66 MHz as the focus of our research. By virtue of the suppression effect of the strong effective field on the magnetic field, the energy level shift caused by the magnetic field was reduced by two orders of magnitude. Combining spectral decomposition techniques, we extracted the electric noise spectrum in the low-frequency range from the environmental noise. Our results indicate that the near-surface electrical noise of the diamond deviates from the 1/f noise model, and two characteristic correlation times were observed within the measured frequency range (1–10 MHz).