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arXiv · 1503.04842

Dzyaloshinskii-Moriya interaction and Hall effects in the skyrmion phase of MnFeGe alloys

J. Gayles·F. Freimuth·T. Schena·G. Lani·P. Mavropoulos·R. Duine·S. Blügel·J. Sinova·Y. Mokrousov
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Abstract

We carry out density functional theory calculations which demonstrate that the electron dynamics in the skyrmion phase of Fe-rich Mn$_{1-x}$Fe$_x$Ge alloys is governed by Berry phase physics. We observe that the magnitude of the Dzyaloshinskii-Moriya interaction, directly related to the mixed space-momentum Berry phases, changes sign and magnitude with concentration $x$ in direct correlation with the data of Shibata {\it et al.}, Nature Nanotech. {\bf 8}, 723 (2013). The computed anomalous and topological Hall effects in FeGe are also in good agreement with available experiments. We further develop a simple tight-binding model able to explain these findings. Finally, we show that the adiabatic Berry phase picture is violated in the Mn-rich limit of the alloys.

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J. Gayles, F. Freimuth, T. Schena, G. Lani, P. Mavropoulos, R. Duine, S. Blügel, J. Sinova, Y. Mokrousov. 2015-03-16. Dzyaloshinskii-Moriya interaction and Hall effects in the skyrmion phase of MnFeGe alloys. https://doi.org/10.1103/physrevlett.115.036602

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