Anomalous and Topological Hall Effects in Antiferromagnetic EuSn2As2 Nanostructures

Evgeny I. Maltsev; Nicolas Pérez; Romain Giraud; Kranthi Kumar Bestha; Anja U. B. Wolter; Joseph Dufouleur; Kirill S. Pervakov; Vladimir M. Pudalov; Kornelius Nielsch; Bernd Büchner; Louis Veyrat

arXiv · 2603.15277

Anomalous and Topological Hall Effects in Antiferromagnetic EuSn2As2 Nanostructures

Evgeny I. Maltsev·Nicolas Pérez·Romain Giraud·Kranthi Kumar Bestha·Anja U. B. Wolter·Joseph Dufouleur·Kirill S. Pervakov·Vladimir M. Pudalov·Kornelius Nielsch·Bernd Büchner·Louis Veyrat

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Abstract

We investigate magnetotransport in exfoliated nanostructures of the candidate magnetic 3D topological insulator $\mathrm{EuSn_{2}As_{2}}$. Similar to macroscopic single crystals, the negative magnetoresistance observed below the N\'eel temperature ($T_N$ = 24 K) is related to the canted antiferromagnetic state (CAF) of an easy-plane antiferromagnet (AFM), with an increase of the saturation field when tilting the applied magnetic field away from the (ab) plane ($\mu_{0} H^{c}_{s}$ = 4.9 T, $\mu_{0} H^{ab}_{s}$ = 3.6 T). Higher-accuracy measurements in nanostructures up to 14 T further evidence a non-linear normal Hall response due to several electronic bands. Interestingly, the transverse resistance due to magnetism reveals an anomalous Hall effect in the CAF state, but also a topological Hall effect due to chiral spin textures, as found in AFM or helical magnets. The presence of real-space chiral spin texture, already reported in another magnetic topological insulator, $\mathrm{MnBi_{2}Te_{4}}$, could be a characteristic generally appearing in magnetic 3D topological insulators.

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Evgeny I. Maltsev, Nicolas Pérez, Romain Giraud, Kranthi Kumar Bestha, Anja U. B. Wolter, Joseph Dufouleur, Kirill S. Pervakov, Vladimir M. Pudalov, Kornelius Nielsch, Bernd Büchner, Louis Veyrat. 2026-03-16. Anomalous and Topological Hall Effects in Antiferromagnetic EuSn2As2 Nanostructures. https://arxiv.org/abs/2603.15277

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