Utilizing Nitrogen Vacancy Centers to measure oscillating magnetic fields

We show how nitrogen vacancy (NV) centers can be used to determine the amplitude, phase and frequency of unknown weak monochromatic and multichromatic oscillating magnetic fields using only the periodic dynamical decoupling (PDD) and Carr-Purcell-Meiboom-Gill (CPMG) sequences. The effect of decoherence on the measurement of the magnetic field parameters is explicitly analyzed, and we take into account the fact that different pulse sequences suppress decoherence to different extents. Since the sensitivity increases with increasing sensing time while it decreases due to decoherence, we use the Fisher information matrix in order to optimize the number of pulses that should be used.