Ultra-sensitive Diamond Magnetometry Using Optimal Dynamic Decoupling
Abstract
New magnetometry techniques based on Nitrogen Vacancy (NV) defects in diamond have received much attention of late as a means to probe nanoscale magnetic environments. The sensitivity of a single NV magnetometer is primarily determined by the transverse spin relaxation time, T2. Current approaches to improving the sensitivity employ crystals with a high NV density at the cost of spatial resolution, or extend T2 via the manufacture of novel isotopically pure diamond crystals. We adopt a complementary approach, in which optimal dynamic decoupling techniques extend coherence times out to the self-correlation time of the spin bath. This suggests single spin, room temperature magnetometer sensitivities as low as 5\,pT\,Hz-1/2 with current technology.