Thermal Conductivity in Vortex State of Nodal Superconductors

Abstract

How to determine the symmetry of the superconducting order parameter is one of the important issues in novel superconductors, which include charge conjugated organic superconductors. We have proposed that the angular dependence of the thermal conductivity in a planar magnetic field provides a new window to look at the symmetry of the order parameter. After a brief summary of the quasiclassical approach we describe how the symmetry of the superconducting order parameter in Sr$_2$RuO$_4$, CeCoIn$_5$ and $κ$-(ET)$_2$Cu(NCS)$_2$ is determined. Also in some of experiments the phononic thermal conductivity plays the crucial role.