Local optical detection of nitrogen concentration in diamond by double electron-electron resonance*

Magnetic impurities in diamond influence the relaxation properties [1] and thus affect the sensitivity of magnetic, electric, strain, and temperature sensors based on nitrogen-vacancy color centers. Diamond samples may exhibit significant spatial variations in the impurity concentrations hindering quantitative analysis of relaxation pathways. Here we present a local-measurement technique which may be used to determine the concentration of different species of defects by utilizing double electron-electron resonance [2]. This method will help to improve the understanding of the underlying physics and will guide the development of diamond samples, as well as offering protocols for optimized sensing.

[1]V. Stepanov and S. Takahashi, Physical Review B 94, 024421 (2016)
[2]A. Jarmola, V. Acosta, K. Jensen, S. Chemerisov, and D. Budker, Physical Review Letters 108, 197601 (2012).