2025/12/10 by Satoru Ohgata, Satoru Hayami, Ohgata, Satoru +1
Physics and Astronomy · Materials Science · #Topological Materials and Phenomena #Chemical and Physical Properties of Materials #Magnetic properties of thin films
paper · pdf · doi:10.48550/arxiv.2512.10168
Multi-Q magnets consist of superposed spin density waves with distinct magnetic modulation vectors, enabling a wide range of magnetic orders depending on their combination. Among them, topologically nontrivial spin textures, such as a magnetic skyrmion, has been extensively studied owing to the emergence of topological Hall effects induced by real-space scalar spin chirality. Contrary to this expectation, we theoretically investigate another route to enhancing the Hall response under a topologically trivial double-Q spin textures. Despite the cancellation of the scalar spin chirality, the double-Q magnetism exhibits a pronounced Hall response with a nonmonotonic dependence on the uniform magnetization, which is in stark contrast to a ferromagnetic state and a single-Q spiral state. Analyzing the multi-orbital Kondo lattice model, we show that orbital hybridization induced by the double-Q superstructure enhances the Berry curvature in k-space, leading to a large anomalous Hall effect. This mechanism accounts for the observed giant anomalous Hall effect in GdRu2Si2 and GdRu2Ge2, thereby highlighting topologically trivial double-Q spin textures as promising spintronic materials.