Topological Nernst and topological thermal Hall effect in rare-earth kagome ScMn$_6$Sn$_6$

TL;DR

This paper demonstrates the presence of topological thermal Hall and Nernst effects in ScMn$_6$Sn$_6$, revealing the influence of Berry curvature in heat transport within its non-coplanar magnetic phases.

Contribution

It provides the first evidence of topological thermal Hall and Nernst effects in the HfFe$_6$Ge$_6$ family, linking real-space and momentum-space topology to heat transport.

Findings

Unconventional increase in Seebeck coefficient below 200 K.

Observation of anomalous thermal Hall and Nernst effects.

Identification of topological contributions to heat transport.

Abstract

Thermal and thermoelectric measurements are known as powerful tools to uncover the physical properties of quantum materials due to their sensitivity towards the scattering and chirality of heat carriers. We use these techniques to confirm the presence of momentum and real-space topology in ScMn$_6$Sn$_6$. There is an unconventional dramatic increase in the Seebeck coefficient on entering the transverse conical spiral (TCS) below $T$ = 200 K suggesting an unusual scattering of heat carriers. In addition, the observed anomalous thermal Hall effect and the anomalous Nernst effect indicates non-zero Berry curvature in $k$-space. Furthermore, we identify a significant topological contribution to the thermal Hall and Nernst signals in the TCS phase revealing the impacts of real-space Berry curvature. We discuss the presence of topological thermal Hall effect and topological Nernst effect for the first time in the diverse HfFe$_6$Ge$_6$ family. This study illustrates the importance of transverse thermal and thermoelectric measurements to investigate the origin of topological transport in the non-coplanar magnetic phases in this family of kagome metals.