Anomalous magnetotransport in a non-collinear correlated kagome ferromagnet MgMn6Sn6

TL;DR

This study investigates the complex magnetotransport phenomena in MgMn6Sn6, a room-temperature kagome ferromagnet with non-collinear magnetic order, revealing significant intrinsic and extrinsic Hall effects influenced by electron correlations.

Contribution

It provides the first combined neutron diffraction and magnetotransport analysis of MgMn6Sn6, highlighting its non-collinear magnetic structure and large intrinsic Hall conductivity.

Findings

Non-collinear Mn magnetic moments within the kagome plane.

Large intrinsic Hall conductivity of about 0.29 e^2/h per layer.

Pronounced anisotropic extrinsic Hall component at low temperatures.

Abstract

Magnetic kagome metals provide a fertile platform for exploring unusual magnetotransport phenomena arising from the intricate interplay between electronic topology, electron correlations, and magnetic order. MgMn6Sn6 is a room-temperature kagome ferromagnet with strong in-plane magnetic anisotropy. Here, we report a combined study of single-crystal neutron diffraction (SCND) and magnetotransport properties of MgMn6Sn6, supported by first-principles calculations. Our SCND measurements reveal a non-collinear arrangement of Mn magnetic moments within the basal plane of the kagome bilayer. The Hall conductivity shows a substantial intrinsic contribution of approximately 0.29 e^2/h per kagome layer, which is nearly isotropic with respect to the field orientation. At low temperatures, the anomalous Hall conductivity develops a pronounced anisotropic extrinsic component, highlighting the directional sensitivity of scattering processes. The significantly large value of the Sommerfeld coefficient, in the absence of f-electrons, underscores enhanced electron correlation. Therefore, the non-collinear kagome ferromagnet MgMn6Sn6 is a promising candidate for studying the effects of electron correlation on magnetotransport properties.