Spin Injection and Detection via the Anomalous Spin Hall Effect of a Ferromagnetic Metal

We report a novel spin injection and detection mechanism via the anomalous Hall effect in a ferromagnetic metal. The anomalous spin Hall effect refers to the transverse spin accumulation generated within the ferromagnet due to the anomalous Hall effect. We utilize the anomalous spin Hall effect and its reciprocal effect to electrically inject and detect magnons in a magnetic insulator (YIG) in a non-local geometry, using a ferromagnetic metal (permalloy). Our experiments reveal that permalloy can have a higher spin injection and detection efficiency to that of platinum, owing to the anomalous spin Hall effect. The discovery of this new effect in ferromagnetic metals opens up the possibility to utilize a variety of ferromagnets as more efficient injectors and detectors of spin currents as compared to expensive heavy metals with high spin-orbit coupling, like platinum. Crucially, we demonstrate that the spin injection and detection via the anomalous spin Hall effect are tunable through the magnetization of the ferromagnet, thus creating new possibilities for spintronic applications.