Anomalous thermal Hall effect and anomalous Nernst effect of CsV3Sb5

Abstract

Motived by time-reversal symmetry breaking and giant anomalous Hall effect in kagome superconductor $A{\mathrm{V}}_{3}{\mathrm{Sb}}_{5}$ ($A$ = Cs, K, Rb), we carried out the thermal transport measurements on $\mathrm{Cs}{\mathrm{V}}_{3}{\mathrm{Sb}}_{5}$. In addition to the anomalous Hall effect, the anomalous Nernst effect and the anomalous thermal Hall effect emerge. Interestingly, the longitudinal thermal conductivity ${\ensuremath{\kappa}}_{xx}$ largely deviates from the electronic contribution obtained from the longitudinal conductivity ${\ensuremath{\sigma}}_{xx}$ by the Wiedemann-Franz law. In contrast, the thermal Hall conductivity ${\ensuremath{\kappa}}_{xy}$ 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 multiband behavior with possible additional contribution from Berry curvature at the low fields.