Magneto-Seebeck effect and ambipolar Nernst effect in the CsV3Sb5 superconductor

Abstract

We present a study of Seebeck and Nernst effect in combination with magnetoresistance and Hall measurements of the Kagome superconductor ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$. A sizable magneto-Seebeck signal appears once the charge density wave (CDW) order sets in below ${T}_{\text{CDW}}=94$ K. The Nernst signal peaks at a lower temperature ${T}^{*}\ensuremath{\sim}35\phantom{\rule{0.16em}{0ex}}\mathrm{K}$, crossing which the Hall coefficient switches sign, which we attribute to the ambipolar transport of compensated bands due to the multiband nature of ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$. Sublinear Nernst signal and Hall resistivity also develop well below the CDW transition, which becomes apparent below ${T}^{*}$. These findings suggest that, the multiband electronic profile plays an important role in the transport properties of the CDW state in ${\mathrm{CsV}}_{3}{\mathrm{Sb}}_{5}$.