Large Anomalous Nernst Effect in a van der Waals Ferromagnet Fe₃GeTe₂

Abstract

Anomalous Nernst effect, a result of charge current driven by temperature gradient, provides a probe of the topological nature of materials due to its sensitivity to the Berry curvature near the Fermi level. Fe₃GeTe₂, one important member of the recently discovered two-dimensional van der Waals magnetic materials, offers a unique platform for anomalous Nernst effect because of its metallic and topological nature. Here, we report the observation of large anomalous Nernst effect in Fe₃GeTe₂. The anomalous Hall angle and anomalous Nernst angle are about 0.07 and 0.09, respectively, far larger than those in common ferromagnets. By utilizing the Mott relation, these large angles indicate a large Berry curvature near the Fermi level, consistent with the recent proposal for Fe₃GeTe₂ as a topological nodal line semimetal candidate. Our work provides evidence of Fe₃GeTe₂ as a topological ferromagnet and demonstrates the feasibility of using two-dimensional magnetic materials and their band topology for spin caloritronics applications.