High-Precision Angle-Resolved Magnetometry with Uniaxial Quantum Centers in Silicon Carbide

Measuring small magnetic moments at the scale of tomorrow's logic devices poses a great challenge. Magnetic resonance of a spin-1 system (such as the N00exV defect in diamond) can be used to measure both strength and orientation of an external magnetic field at the nanoscale under ambient conditions, i.e. without cryogenic cooling, but angle resolution decreases rapidly for a weak field. The authors demonstrate that using instead a spin-3/2 system (here the uniaxial Si vacancy in SiC) can significantly improve angle sensitivity, even for fields under 1 mT.