Anomalous Hall conductivity control in Mn3NiN antiperovskite by epitaxial strain along the kagome plane

Antiferromagnetic manganese-based nitride antiperovskites, such as Mn3NiN, hold a triangular frustrated magnetic ordering, thanks to their kagome lattice formed by the Mn atoms along the (111) plane. As such, the magnetic frustration imposes a nontrivial interplay between the symmetric and asymmetric magnetic interac-tions, which can only reach equilibrium in a noncollinear magnetic configuration. Consequently, the associated electronic interactions and their possible tuning by external constraints, such as applied epitaxial strain, play a crucial role in defining the microscopic and macroscopic properties of such topological condensed matter systems. In this paper, we explored and explained the effect of the epitaxial strain imposed within the (111) plane, in which the magnetic and crystallographic symmetry operations are kept fixed, and only the magnitude of the ionic and electronic interactions are tuned. We found a tangible enhancement in the anomalous Hall conductivity along the (111) plane (aAHE 111 ) for compression values, whereas, for tension, the AHC is dramatically reduced. As such, the aAHE 111 component fetches a maximum increase of 26%, with respect to the unstrained structure, for a compression value close to-1.5%. Our findings indicate a distinct correlation between the anomalous Hall conductivity and the Berry curvature along the (111) plane as a function of the strain. Here, the nondivergent Berry curvature acts as the source and the strain as the control mechanism of this anomalous transport phenomenon.

Automated summary

In this study, we investigated the effect of epitaxial strain imposed within the (111) plane on the conductivity and Berry curvature of antiferromagnetic manganese-based nitride antiperovskites. We found that compression significantly enhances the anomalous Hall conductivity, while tension dramatically reduces it. This suggests that strain can act as a control mechanism for anomalous transport phenomena.