Field-induced topological Hall effect in antiferromagnetic axion insulator candidate EuIn₂As₂

Intrinsic magnetic topological materials provide a more fertile playground to give rise to nontrivial topological phases, such as a quantum anomalous Hall effect and axion insulator states. EuIn₂As₂ has been theoretically recognized as a long-awaited intrinsic antiferromagnetic bulk axion insulator. In this talk, we will discuss the magnetotransport properties of this material through our magnetoresistance (MR) and Hall measurements. The concomitant field dependence of MR and that of magnetization observed below the Néel temperature provide evidence that the transport phenomena are strongly influenced by the spin configuration of the Eu moment in this system. Most importantly, an anomalous Hall effect (AHE) and a large topological Hall effect (THE) are observed. We suggest that the AHE originated from a nonvanishing net Berry curvature due to the helical spin structure. The THE is caused by the formation of a noncoplanar spin texture induced by the external magnetic field in EuIn₂As₂. Our studies provide a platform to understand the influence of the interplay between the topology of electronic bands and field-induced magnetic structure on magnetoelectric transport properties.