Suppression of Spin Noise in Diamond for improved Sensing and Imaging

Increasing the coherence time of nitrogen vacancy (NV) center spins in diamond is of great interest for quantum information, sensing and metrology applications. However, achieving long coherence times remains a challenge in dense samples, where the NV's $T_2$ is limited by electronic spin-spin interaction of the nitrogen donors in the lattice. In these samples, nuclear spin impurities associated with the $^{13}$C isotopes can suppress the dominant nitrogen electronic spin bath by reducing the flip-flop rates and enhancing the NV's coherence time. We investigate this spin bath suppression effect both experimentally and theoretically and provide a pathway to engineering high density NV samples with sufficiently long coherence times.