Optically Enhanced Electric Field Sensing Using Nitrogen-Vacancy Ensembles

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.