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arXiv · 2012.06088

Anomalous Hall resistivity and possible topological Hall effect in the EuAl$_4$ antiferromagnet

T. Shang·Y. Xu·D. J. Gawryluk·J. Z. Ma·T. Shiroka·M. Shi·E. Pomjakushina
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Abstract

We report the observation of anomalous Hall resistivity in single crystals of EuAl$_4$, a centrosymmetric tetragonal compound, which exhibits coexisting antiferromagnetic (AFM) and charge-density-wave (CDW) orders with onset at $T_\mathrm{N} \sim 15.6$ K and $T_\mathrm{CDW} \sim 140$ K, respectively. In the AFM state, when the magnetic field is applied along the $c$-axis direction, EuAl$_4$ undergoes a series of metamagnetic transitions. Within this field range, we observe a clear hump-like anomaly in the Hall resistivity, representing part of the anomalous Hall resistivity. By considering different scenarios, we conclude that such a hump-like feature is most likely a manifestation of the topological Hall effect, normally occurring in noncentrosymmetric materials known to host nontrivial topological spin textures. In view of this, EuAl$_4$ would represent a rare case where the topological Hall effect not only arises in a centrosymmetric structure, but it also coexists with CDW order.

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T. Shang, Y. Xu, D. J. Gawryluk, J. Z. Ma, T. Shiroka, M. Shi, E. Pomjakushina. 2020-12-11. Anomalous Hall resistivity and possible topological Hall effect in the EuAl$_4$ antiferromagnet. https://doi.org/10.1103/physrevb.103.l020405

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