Topological Hall effect instigated in kagome Mn3-xSn due to Mn-deficit induced noncoplanar spin structure.

Abstract

Magnetic topological semimetals are manifestations of the interplay between electronic and magnetic phases of matter, leading to peculiar characteristics such as the anomalous Hall effect (AHE) and the topological Hall effect (THE). Mn₃Sn is a time-reversal symmetry-broken magnetic Weyl semimetal showing topological characteristics within the Kagome lattice network. This study reveals a large THE in Mn_2.8Sn (6% Mn deficit Mn₃Sn) at room temperature in thexy-plane, despite being an antiferromagnet. We argue that the magnetocrystalline anisotropy induced noncoplanar spin structure is responsible for the observed THE in these systems. Further, the topological properties of these systems are highly anisotropic, as we observe a large AHE in thezx-plane. We find that Fe doping at the Mn site, Mn3-xFe_xSn (x= 0.2, 0.25, & 0.35), tunes the topological properties of these systems. These findings promise the realization of potential topotronic applications at room temperature.