Gigantic Anisotropy of Self-Induced Spin-Orbit Torque in Weyl Ferromagnet Co2MnGa

Spin-orbittorque (SOT) is receiving tremendous attention fromboth fundamental and application-oriented aspects. Co2MnGa,a Weyl ferromagnet that is in a class of topological quantum materials,possesses cubic-based high structural symmetry, the L2(1) crystal ordering, which should be incapable of hosting anisotropicSOT in conventional understanding. Here we show the discovery of agigantic anisotropy of self-induced SOT in Co2MnGa. Themagnitude of the SOT is comparable to that of heavy metal/ferromagnetbilayer systems, despite the high inversion symmetry of the Co2MnGa structure. More surprisingly, a sign inversion of theself-induced SOT is observed for different crystal axes. This findingstems from the interplay of the topological nature of the electronicstates and their strong modulation by external strain. Our researchenriches the understanding of the physics of self-induced SOT anddemonstrates a versatile method for tuning SOT efficiencies in a widerange of materials for topological and spintronic devices.