  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.
