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arXiv · 2211.12722

Higher order exchange driven noncoplanar magnetic state and large anomalous Hall effects in electron doped kagome magnet Mn$_3$Sn

Charanpreet Singh·Sk Jamaluddin·Ashis K. Nandy·Masashi Tokunaga·Maxim Avdeev·Ajaya K. Nayak
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Abstract

Owing to the geometrical frustration, Mn$_3 $Sn exhibits a 120$^{\circ}$ in-plane triangular antiferromagnetic (AFM) order with a large anomalous Hall effect (AHE). Here, we present a combined theoretical and experimental study to demonstrate that the in-plane AFM structure in Mn$_3 $Sn can be significantly modified to a tunable noncoplanar magnetic state by suitable electron doping. With the help of Density Functional Theory calculations we show that the presence of higher-order exchange interactions in the system leads to the stabilization of the noncoplanar magnetic ground state, which is further established by neutron diffraction study in the Fe-doped Mn$_3 $Sn sample. Interestingly, we find a large scalar spin chirality (SSC) induced topological AHE that can be significantly tuned with the degree of non-coplanarity. We carry out 60~T magnetic and Hall resistivity measurements to demonstrate the contribution of SSC to the observed AHE. We also illustrate a simultaneous manipulation of dual order in the system, where the AHE arising from the in-plane 120$^{\circ}$ triangular AFM order can switch its sign without affecting the AHE generated by the SSC. The present study opens up a new direction to explore novel quantum phenomena associated with the coexistence of multiple orders.

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Charanpreet Singh, Sk Jamaluddin, Ashis K. Nandy, Masashi Tokunaga, Maxim Avdeev, Ajaya K. Nayak. 2022-11-23. Higher order exchange driven noncoplanar magnetic state and large anomalous Hall effects in electron doped kagome magnet Mn$_3$Sn. https://doi.org/10.1038/s41535-024-00657-z

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