Thermal Transport in 2D Nematic Superconductors

Thermal conductivity measurements are a very useful probe of superconductivity as it can reveal the gap structure of unconventional superconductors. Here we study thermal transport in a two-dimensional system with coexisting Superconducting (SC) and Nematic orders. We treat both the superconducting and nematic orders within the mean field approximation. A d-wave Pomeranchuk instability was used to model the nematic state and the feedback of the symmetry-broken nematic state on the SC channel was modeled through the mixing of s- and d-wave components. The electronic thermal conductivity was calculated within the framework of Boltzmann kinetic theory, for both the Born and Unitary limits. We describe the influence of the Fermi surface (FS) topology, the competition/cooperation between the SC and Nematic order parameters, the effect of the nematic feedback on the SC order, on the low temperature behaviour of thermal conductivity. Numerical results obtained point to novel heat transport signatures of nematic superconductors. This work was supported by the National Science Foundation under grants DMR1906383 and DMR1809846.