Anomalous thermal Hall effect and anomalous Nernst effect of CsV$_{3}$Sb$_{5}$

TL;DR

This study investigates the anomalous thermal Hall and Nernst effects in CsV₃Sb₅, revealing significant phonon contributions and potential Berry curvature effects, advancing understanding of thermal transport in kagome superconductors.

Contribution

The paper reports the observation of anomalous thermal Hall and Nernst effects in CsV₃Sb₅, highlighting phonon contributions and possible Berry curvature influence in thermal transport.

Findings

Anomalous Nernst and thermal Hall effects are observed.

Longitudinal thermal conductivity deviates from electronic predictions.

Thermal Hall conductivity exceeds electronic contributions, indicating other effects.

Abstract

Motived by time-reversal symmetry breaking and giant anomalous Hall effect in kagome superconductor \textit{A}V$_3$Sb$_5$ (\textit{A} = Cs, K, Rb), we carried out the thermal transport measurements on CsV$_3$Sb$_5$. In addition to the anomalous Hall effect, the anomalous Nernst effect and the anomalous thermal Hall effect emerge. Interestingly, the longitudinal thermal conductivity $\kappa_{xx}$ largely deviates from the electronic contribution obtained from the longitudinal conductivity $\sigma_{xx}$ by the Wiedemann-Franz law. In contrast, the thermal Hall conductivity $\kappa_{xy}$ is roughly consistent with the Wiedemann-Franz law from electronic contribution. All these results indicate the large phonon contribution in the longitudinal thermal conductivity. Moreover, the thermal Hall conductivity is also slightly greater than the theoretical electronic contribution, indicating other charge neutral contributions. More than that, the Nernst coefficient and Hall resistivity show the multi-band behavior with possible additional contribution from Berry curvature at the low fields.