Thermal Transport in 2D Nematic Superconductors

TL;DR

This paper investigates how nematic order influences thermal transport in 2D superconductors, revealing distinct heat conduction signatures that depend on the anisotropy of the superconducting gap and Fermi surface topology.

Contribution

It provides a detailed analysis of thermal conductivity in nematic superconductors, incorporating impurity scattering effects and the interplay between nematic and superconducting orders.

Findings

Thermal conductivity varies with gap anisotropy and Fermi surface features.

Nematicity induces observable signatures in heat transport.

The study distinguishes between different impurity scattering regimes.

Abstract

We study the thermal transport in a two-dimensional system with coexisting superconducting (SC) and nematic orders. We analyze the nature of the coexistence phase in a tight-binding square lattice where the nematic state is modelled as a $d$-wave Pomeranchuk type instability and the feedback of the symmetry breaking nematic state on the SC order is accounted for by mixing of the $s$, $d$ paring interaction. The electronic thermal conductivity is computed within the framework of Boltzmann kinetic theory where the impurity scattering collision is treated in the both the Born and Unitary limits. We present qualitative, analytical, and numerical results that show that the heat transport properties of SC states emerging from a nematic background are quite distinct and depend on the degree of anisotropy of the SC gap induced by nematicity. We describe the influence of the Fermi surface topology, the van Hove singularities, and the presence or absence of zero energy excitations in the coexistence phase on the the low temperature behaviour of the thermal conductivity. Our main conclusion is that the interplay of nematic and SC orders has visible signatures in the thermal transport which can be used to infer SC gap structure in the coexistence phase.