Comparison of dynamical decoupling applied to nitrogen-vacancy (NV) and substitutional nitrogen (P1) centers in diamond at 2.5 GHz

Using inductively-detected pulsed ESR, we make stroboscopically observed ensemble measurements of both the nitrogen-vacancy (NV) and the substitutional nitrogen (P1) center under application of dynamical decoupling (DD) pulse sequences which effectively reduce noise and interactions that limit T2. We compare the effectiveness of various DD sequences for both defects in diamond samples containing either low (1 ppm) or high (100 ppm) P1 concentrations. At low P1 concentrations the low-frequency noise spectra are dominated by the carbon-13 nuclear spins. Since the resonant magnetic fields required for the NV (13 mT) and P1 (89 mT) centers are different in our fixed 2.5 GHz spectrometer, we are able to probe the field dependence of the nuclear spin noise. We also study NV-P1 interactions and the hyperpolarization of P1 centers. These results are significant for understanding the local magnetic noise environment in diamond-based sensors and for developing hyperpolarization strategies in diamond magnetometry.