Controllable anomalous Nernst effect in an antiperovskite antiferromagnet

TL;DR

This paper demonstrates controllable anomalous Nernst effect in an antiperovskite antiferromagnet Mn3SnN, driven by Berry curvature from Weyl points, with strain tuning enabling modulation of the effect, advancing antiferromagnetic spin caloritronics.

Contribution

It reports the first experimental observation of ANE in Mn3SnN and shows how biaxial strain can modulate this effect in antiperovskite noncollinear AFM materials.

Findings

ANE observed in Mn3SnN due to Weyl points near Fermi level

Biaxial strain modulates the noncollinear AFM configurations and ANE

Potential for energy conversion and spin caloritronics applications

Abstract

Anomalous Nernst effect (ANE), the generation of a transverse electric voltage by a longitudinal temperature gradient, has attracted increasing interests of researchers recently, due to its potential in the thermoelectric power conversion and close relevance to the Berry curvature of the band structure. Avoiding the stray field of ferromagnets, ANE in antiferromagnets (AFM) has the advantage of realizing highly efficient and densely integrated thermopiles. Here, we report the observation of ANE in an antiperovskite noncollinear AFM Mn3SnN experimentally, which is triggered by the enhanced Berry curvature from Weyl points located close to the Fermi level. Considering that antiperovskite Mn3SnN has rich magnetic phase transition, we modulate the noncollinear AFM configurations by the biaxial strain, which enables us to control its ANE. Our findings provide a potential class of materials to explore the Weyl physics of noncollinear AFM as well as realizing antiferromagnetic spin caloritronics that exhibits promising prospects for energy conversion and information processing.