Thermal Conductivity in Vortex State of Nodal Superconductors

TL;DR

This paper proposes using the angular dependence of thermal conductivity in a magnetic field as a new method to determine the symmetry of the superconducting order parameter in unconventional superconductors, supported by quasiclassical analysis.

Contribution

It introduces a novel approach to identify the order parameter symmetry via thermal conductivity measurements in vortex states of nodal superconductors.

Findings

Determined the symmetry of the order parameter in Sr₂RuO₄, CeCoIn₅, and κ-(ET)₂Cu(NCS)₂.

Highlighted the importance of phononic thermal conductivity in experiments.

Provided a quasiclassical framework for analysis.

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 $\kappa$-(ET)$_2$Cu(NCS)$_2$ is determined. Also in some of experiments the phononic thermal conductivity plays the crucial role.