Multi-parameter study of a diamond magnetometer

Negatively charged nitrogen-vacancy (NV) diamond magnetometers are promising candidates for room-temperature magnetic field sensing. However, systematic studies of magnetic field sensors that evaluate the sensitivity of NV-diamond magnetometers as a function of multiple parameters are sparse. By comparing optically detected magnetic resonance (ODMR) dips for four single-crystal diamonds, we explored how the photon shot-noise-limited sensitivity and experimental magnetic noise floor were influenced by the density of the NV centers and methods of their formation. The lowest shot-noise-limited sensitivity was 380 pT/√Hz; it was significantly affected by ODMR fluorescence, contrast, and linewidth. Using dual-resonance modulation in ODMR, the experimental lowest magnetic noise floor based on power spectral density was 1.14 nT/√Hz. These values can be improved with an increase in laser power. This study will facilitate the selection of appropriate NV diamonds when designing magnetometers for various applications.

DOI 10.1088/1361-6463/ada6cb