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arXiv · 1904.11410

Thickness dependence of the anomalous Hall effect in thin films of the topological semimetal Co$_2$MnGa

Anastasios Markou·Dominik Kriegner·Jacob Gayles·Liguo Zhang·Yi-Cheng Chen·Benedikt Ernst·Yu-Hong Lai·Walter Schnelle·Ying-Hao Chu·Yan Sun·Claudia Felser
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Abstract

Topological magnetic semimetals promise large Berry curvature through the distribution of the topological Weyl nodes or nodal lines and further novel physics with exotic transport phenomena. We present a systematic study of the structural and magnetotransport properties of Co$_2$MnGa films from thin (20 nm) to bulk like behavior (80 nm), in order to understand the underlying mechanisms and the role on the topology. The magnetron sputtered Co$_2$MnGa films are $L$$2_{\mathrm {1}}$-ordered showing very good heteroepitaxy and a strain-induced tetragonal distortion. The anomalous Hall conductivity was found to be maximum at a value of 1138 S/cm, with a corresponding anomalous Hall angle of 13 %, which is comparatively larger than topologically trivial metals. There is a good agreement between the theoretical calculations and the Hall conductivity observed for the 80 nm film, which suggest that the effect is intrinsic. Thus, the Co$_2$MnGa compound manifests as a promising material towards topologically-driven spintronic applications.

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Anastasios Markou, Dominik Kriegner, Jacob Gayles, Liguo Zhang, Yi-Cheng Chen, Benedikt Ernst, Yu-Hong Lai, Walter Schnelle, Ying-Hao Chu, Yan Sun, Claudia Felser. 2019-04-25. Thickness dependence of the anomalous Hall effect in thin films of the topological semimetal Co$_2$MnGa. https://doi.org/10.1103/physrevb.100.054422

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