Theory of Topological Nernst and Thermoelectric Transport in Chiral Magnets

Abstract

We calculate the thermoelectric transport of spin-orbit coupled conduction electrons in the presence of topological spin textures. We show, within a controlled, semiclassical approach that includes all phase space Berry curvatures, that the Nernst effect has two contributions in addition to the usual effect proportional to a magnetic field. These are an anomalous contribution governed by the momentum-space Berry curvature and proportional to net magnetization, and a topological contribution determined by the real-space Berry curvature and proportional to the topological charge density, which is non-zero in skyrmion phases. We derive a generalized Mott relation expressing the thermoelectric tensor as the chemical potential derivative of the conductivity tensor and show how the Sondheimer cancellation in the Nernst effect is evaded in chiral magnets.