Ensembles of nitrogen-vacancy (N-
V) centers in diamond show promise as versatile electric field sensors, but are limited by noise from an inhomogeneous internal charge environment. Here researchers develop a scheme for optically enhanced electrometry that improves N-
V sensitivity to external electric fields, especially at low temperatures. They also implement a complementary method for experimentally extracting the color center's excited-state electric field susceptibilities, and they provide a simple scaling theory for optimizing the density of N-
V defects in electrometry applications.
We report measurements of optically detected magnetic resonance spectra of ensembles of nitrogen-vacancy (NV-) centers in diamonds in the presence of electromagnetic fields. To reduce inhomogeneous broadening, the spectra are acquired from a region of 20 cubic microns in a CVD(Chemical Vapor Deposition) diamond through a confocal microscope. The Stark shift from transverse electric fields is enhanced at avoided crossings between the hyperfine levels that arise from interaction with 14N(I = 1) nuclei in the diamond lattice. As expected from previous reports, the Stark shift of the spectral lines is stronger when there is no magnetic field along the NV axis. The shift is also strong, but for different transitions, at a field of about 100 uT.
Abstract Nitrogen-vacancy (NV) center ensembles in diamond are one of the most promising solid-state quantum platforms for various sensing applications. Achieving ultimate sensitivity requires simultaneously long spin dephasing times (
T2∗ T 2 * ) and high NV center concentrations. In this work, we propose a systematic measurement approach to quantify the electron spin dephasing in NV center ensembles and analyze the contributions of various sources to the dephasing time, including NV-NV interactions, strain and electric field distributions, 13 C nuclear spins, and P1 electron spins. Our method is validated using a series of high-performance diamond samples, providing a comprehensive understanding of dephasing mechanisms and revealing correlations between NV concentration and different dephasing sources. Building on these insights, we outline strategies to further enhance the achievable sensitivity for DC magnetic field measurements.