Exchange-biased topological transverse thermoelectric effects in a Kagome ferrimagnet

TL;DR

This paper reports large anomalous Nernst and thermal Hall effects in the Kagome ferrimagnet TbMn6Sn6, driven by Berry curvature from Dirac gaps, with exchange-bias behavior enhancing thermoelectric performance.

Contribution

It demonstrates the observation of exchange-biased transverse thermoelectric effects in a topological Kagome ferrimagnet, supported by first-principles calculations.

Findings

Large anomalous Nernst effect observed

Anomalous thermal Hall effect confirmed

Exchange-bias behavior in thermoelectric transport

Abstract

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.