1National Laboratory of Solid State Microstructures & School of Physics, Nanjing University, Nanjing 210093 2Department of Physics, Ningbo University, Ningbo 315211 3Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093
Abstract：The universal behavior of thermal conductivity at low temperatures is usually taken as the signature of gap nodes in superconductors. Here we show that in near-nodal superconductors the thermal conductivity obeys a two-parameter scaling law, and can develop super-universal behavior if the temperature is about half the gap minimum. However, when the temperature is fixed at about one quarter of the gap minimum, the thermal conductivity can develop a dip versus the scattering rate, which is in excellent agreement with the behavior of the experimental thermal conductivity in Sr$_2$RuO$_4$. Our theory is useful to correctly analyze the thermal conductivity in any near-nodal superconductor.
Hassinger E, Bourgeois-Hope P, Taniguchi H, René de Cotret S, Grissonnanche G, Anwar M S, Maeno Y, Doiron-Leyraud N and Taillefer L 2017 Phys. Rev. X 7 011032
2018, Vol. 35 
