Multiphase superconductivity in skutterudite

¹ Department of Physics and Astronomy, University of Southern California Los Angeles, CA 90089-0484, USA
² Department of Physics, Hallym University - Chuncheon 200-702, South Korea
³ Max Planck Institute for the Chemical Physics of Solids - Dresden, Germany
⁴ Pohl Institute of Solid State Physics, Tongji University - Shanghai 200092, PRC
⁵ Institute for Solid State Physics, University of Tokyo Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8581, Japan

Corresponding author: kmaki@usc.edu

Received: 23 July 2003
Accepted: 8 September 2003

Abstract

We propose a model of nodal order parameters for the superconducting A- and B-phase of skutterudite and discuss the associated angular-dependent magnetothermal conductivity at low temperatures. The model for the hybrid gap functions containing s- and g-wave parts is consistent with recent thermal-conductivity experiments in . In particular, the model accounts for the data on the polar and azimuthal field angle dependence of . The low-temperature behaviour of thermodynamic properties in zero field is also presented. We show that the effect of impurity scattering on a nodal hybrid gap function immediately leads the opening of a gap and the related exponential behaviour of low-temperature specific heat and thermal conductivity which is very different from d-wave superconductors.