Effect of Lishitz Transition on Thermal Transport Properties in Sr2RuO4

Inspired by specific features of the spin-triplet superconductor Sr2RuO4, we investigate thermal transport properties for a generic chiral p-wave superconductor. One of the bands of Sr2RuO4 lies close to a Lifshitz transition which would lead to a change of the Fermi surface topology and influence also topological properties of the chiral superconducting phase characterized by the so-called Chern number. Treating superconductivity based on a two-dimensional tight-binding model for the relevant γ band and a self-consistent Bogoliubov-de Gennes approach, we study thermal transport properties. We focus particularly on the connection between topological properties of the superconducting phase and thermal Hall conductivity. Our results show that low-temperature thermal Hall conductivity can be decomposed into a T -linear contribution and an thermally activated correction, whereby the latter incorporates information about the size of the superconducting gap and the Lifshitz transition.