Mapping the Stray Fields of a Micromagnet Using Spin Centers in SiC

In this letter, we report the use of optically addressable spin centers in SiC to probe the static magnetic stray fields generated by a ferromagnetic microstructure lithographically patterned on the surface of a SiC crystal. The stray fields cause shifts in the resonance frequency of the spin centers. The spin resonance in the spin centers is driven by a micrometer-sized microwave antenna patterned adjacent to the magnetic element. The patterning of the antenna is done to ensure that the driving microwave fields are delivered locally and more efficiently compared to conventional, millimeter-sized circuits. A clear difference in the resonance frequency of the spin centers in SiC is observed at various distances to the magnetic element, for two different magnetic states. Our results are a first step toward developing magnon-quantum applications by deploying the local microwave fields and the stray fields at the micrometer length scale.