Nodal line induced large transverse thermoelectric response in the D03-type Heusler compound Fe3Si

Giant magnetic transverse thermoelectric effect, anomalous Nernst effect (ANE), was theoretically and experimentally observed in $3d$-transition metal compounds. The intrinsic components of ANE can be described from the electronic structure based on the Berry phase concept. The topological electronic structure, such as the Weyl node and nodal lines, induces large Berry curvature, one origin of giant ANE. We investigated transverse thermoelectric properties on ferromagnetic $\mathrm{D}{0}_3$-type Heusler compounds ${\mathrm{Fe}}_3\mathrm{Si}$ based on first-principles calculations. We found large transverse thermoelectric conductivity ${\alpha }_{xy}\sim 5{\mathrm{AK}}^{-1}{\mathrm{m}}^{-1}$ is realized with hole carrier doping at room temperature. We also clarified that the nodal line and its stationary point enhance transverse thermoelectric conductivity. These results give us a clue to design high-performance ANE-based magnetic thermoelectric materials.