Large anomalous Nernst effect and topological Nernst effect in the noncollinear antiferromagnet NdMn2Ge2

Abstract

ThCr2Si2-type NdMn2Ge2 was recently proposed to be a magnetic skyrmion candidate exhibiting the topological Hall effect. In this work, we report magnetic, electronic, and thermoelectric measurements for NdMn2Ge2 single crystals. We show that, in the canted antiferromagnetic phase and the conical magnetic phase with a large out-of-plane ferromagnetic component, this system exhibits both an anomalous Nernst effect and a topological Nernst effect. We argue that NdMn2Ge2 is a unique magnetic material, with its topological characteristics associated with the Berry phases in both real space and momentum space.