Longitudinal Spin Relaxation in Nitrogen-Vacancy Defect Centers in Diamond

The negatively-charged nitrogen-vacancy (NV$^-$) color center in diamond is used in a range of applications, including quantum information and sensing. The longitudinal electronic spin relaxation time ($T_1$) of the NV ground-state magnetic sublevels is used for sensing paramagnetic spins, and $T_1$ represents a limitation to the NV spin-noise sensitivity. However, some fundamental aspects of $T_1$ relaxation remain a mystery, which we aim to resolve. We present the results of experimental NV $T_1$ studies done at the University of California Berkeley with collaborating laboratories.