Topological Nernst and topological thermal Hall effect in rare-earth kagome <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>ScMn</mml:mi><mml:mn>6</mml:mn></mml:msub><mml:msub><mml:mi>Sn</mml:mi><mml:mn>6</mml:mn></mml:msub></mml:mrow></mml:math>
Richa P. Madhogaria, Shirin Mozaffari, Heda Zhang, William R. Meier, Seung-Hwan Do, Rui Xue, T. Matsuoka, David Mandrus
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 ${\mathrm{ScMn}}_{6}{\mathrm{Sn}}_{6}$. There is an unconventional dramatic increase in the Seebeck coefficient on entering the transverse conical spiral (TCS) state below $T=200$ K, suggesting an unusual scattering of heat carriers. In addition, the observed anomalous thermal Hall effect and the anomalous Nernst effect indicate nonzero 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 the topological thermal Hall effect and topological Nernst effect in the diverse ${\mathrm{HfFe}}_{6}{\mathrm{Ge}}_{6}$ family. This study illustrates the importance of transverse thermal and thermoelectric measurements to investigate the origin of topological transport in the noncoplanar magnetic phases in this family of kagome metals.