Self-generated anomalous Hall spin-orbit torque

Spin-orbit torques (SOTs) are relativistic quantum mechanical effects that enable energy-efficient manipulation of magnetization by electric current. SOTs can be generated in bilayers of ferromagnetic (FM) and non-magnetic (NM) materials with broken inversion symmetry. The earliest and most well-known spin-orbit torques originate from spin Hall effect in the NM layer and Rashba effect at the NM/FM interface. Recently, we demonstrated that the planar Hall current in a FM can lead to a giant SOT applied to the same FM – an example of a new class of self-generated SOTs. In this talk, we will report the discovery of a giant self-generated SOT associated with the anomalous Hall effect (AHE) in the FM. This new SOT displays an unusual angular symmetry that is distinct from the previously studied spin Hall, Rashba, and planar Hall torques. Furthermore, we demonstrate that the strength of the anomalous Hall SOT can be tuned via Berry curvature and filling of the FM electronic bands in the same manner as the AHE magnitude.