Spin Seebeck and Spin Nernst Effects of Magnons in Noncollinear Antiferromagnetic Insulators

Abstract

Our joint theoretical and computer experimental study of heat-to-spin conversion reveals that noncollinear antiferromagnetic insulators are promising materials for generating magnon spin currents upon application of a temperature gradient: they exhibit spin Seebeck and spin Nernst effects. Using Kubo theory and spin dynamics simulations, we explicitly evaluate these effects in a single kagome sheet of potassium iron jarosite, KFe${}_3$(OH)${}_6$(SO${}_4$)${}_2$, and predict a spin Seebeck conversion factor of $0.2\mu \mathrm{V}/\mathrm{K}$ at a temperature of $20\mathrm{K}$.

6 pages, 3 figures