Identification of the intrinsic, topological, and extrinsic anomalous Hall effects in noncollinear antiferromagnets

The emergence of the anomalous Hall effect (AHE) in noncollinear antiferromagnets (AFMs) challenges the conventional notion that this phenomenon is exclusive to ferromagnets and primarily driven by spin-orbit coupling. However, the mechanisms contributing to this effect in such materials are often entangled, making distinctions difficult. Here, we discovered a giant AHE in a noncollinear AFM Mn₃Pd film and investigated its origin with experimental and theoretical methods to address this complexity. Our findings reveal that the anomalous Hall resistance adheres to a new linear scaling law that facilitates the clear identification of the intrinsic Berry curvature, the scalar spin-chirality-induced topological AHE, and the extrinsic side-jump scattering AHE. Furthermore, we demonstrate that this scaling law is universally applicable to various noncollinear AFMs and altermagnets. This work enhances our understanding of the complex origins of the AHE in AFMs and paves the way for advancements in AFM spintronics.