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

Abstract

Magnetic topological materials have attracted significant attention due to their potential realization of a variety of novel quantum phenomena. ${\mathrm{EuIn}}_{2}{\mathrm{As}}_{2}$ has recently been theoretically recognized as a long-awaited intrinsic antiferromagnetic bulk axion insulator. However, experimental studies of the transport properties arising from the topological states in this material are scarce. In this paper, we perform detailed magnetoresistance (MR) and Hall measurements to study the magnetotransport properties of this material. We find that the transport is strongly influenced by the spin configuration of the Eu moments from the concomitant change in the field dependence of the MR and that of the magnetization below the N\'eel temperature. Most importantly, an anomalous Hall effect (AHE) and a large topological Hall effect (THE) are observed. We suggest that the AHE is originated from a nonvanishing net Berry curvature due to the helical spin structure and that the THE is attributed to the formation of a noncoplanar spin texture with a finite scalar spin chirality induced by the external magnetic field in ${\mathrm{EuIn}}_{2}{\mathrm{As}}_{2}$. Our studies provide a platform to understand the influence of the interplay between the topology of electronic bands and the field-induced magnetic structure on magnetoelectric transport properties. In addition, our observations give a hint to realize axion insulator states and higher-order topological insulator states through manipulating the magnetic state of ${\mathrm{EuIn}}_{2}{\mathrm{As}}_{2}$.