Signature of magnon Nernst effect in an antiferromagnetic insulator*

A magnon Nernst effect, an antiferromagnetic analog of the magnon Hall effect in ferromagnetic insulators, has been studied experimentally for the layered antiferromagnetic insulator MnPS₃ in contact with two Pt strips [Y. Shiomi, R. Takashima, and E. Saitoh, Phys. Rev. B 96, 134425 (2017)]. Thermoelectric voltage in the Pt strips grown on MnPS₃ single crystals exhibits nonmonotonic temperature dependence at low temperatures, which is unlikely to be explained by electronic origins in Pt but can be ascribed to the inverse spin Hall voltage induced by a magnon Nernst effect. Control of antiferromagnetic domains in the MnPS₃ crystal by magnetoelectric cooling is found to modulate the low-temperature thermoelectric voltage in Pt, which is evidence consistent with the emergence of the magnon Nernst effect in Pt-MnPS₃ hybrid structures.