Quantum sensing with solid state spins

Detection of AC magnetic fields at the nanoscale is critical in applications ranging from fundamental physics to materials science. Isolated nitrogen-vacancy centers in diamond can achieve the desired spatial resolution with high sensitivity. Still, there are several limitations to their applicability, ranging from a reduced spectral range to limited capabilities in detecting vectorial information. For example, vector AC magnetometry currently relies on using different orientations of an ensemble of sensors, with degraded spatial resolution. Control methods based on Floquet driving can open new opportunities and broaden the scope of applicability of spin sensors. Here I will present a novel protocol that exploits a single NV to reconstruct the vectorial components of an AC magnetic field, by tuning a continuous driving to distinct resonance conditions. As an experimental proof-of-principle, I’ll show how to map the spatial distribution of an AC field generated by a copper wire on the surface of the diamond. The proposed protocol combines high sensitivity, broad dynamic range, and sensitivity to both coherent and stochastic signals, with broad applications in condensed matter physics.