Exchange-biased topological transverse thermoelectric effects in a Kagome ferrimagnet

Kagome metal TbMn6Sn6 was recently discovered to be a ferrimagnetic topological Dirac material. Here, the authors observe anomalous Nernst effect and anomalous thermal Hall effect which exhibit asymmetry with respect to the magnetic field. Kagome metal TbMn6Sn6 was recently discovered to be a ferrimagnetic topological Dirac material by scanning tunneling microscopy/spectroscopy measurements. Here, we report the observation of large anomalous Nernst effect and anomalous thermal Hall effect in this compound. The anomalous transverse transport is consistent with the Berry curvature contribution from the massive Dirac gaps in the 3D momentum space as demonstrated by our first-principles calculations. Furthermore, the transverse thermoelectric transport exhibits asymmetry with respect to the applied magnetic field, i.e., an exchange-bias behavior. Together, these features place TbMn6Sn6 as a promising system for the outstanding thermoelectric performance based on anomalous Nernst effect.

Automated summary

This study discovers that kagome metal TbMn6Sn6 is a ferrimagnetic topological Dirac material and observes its asymmetrical anomalous Nernst effect and anomalous thermal Hall effect. First-principles calculations demonstrate that the anomalous transverse transport is consistent with the Berry curvature contribution from the massive Dirac gaps in the 3D momentum space. Additionally, the transverse thermoelectric transport exhibits an exchange-bias behavior with respect to the applied magnetic field.