Multiband Order Parameters For The Pros_4sb_(12) And Prru_4sb_(12) Skutterudite Superconductors From Thermal Conductivity Measurements

摘要

Thermal conductivity measurements were performed on single crystal samples of the superconducting filled-skutterudite compounds PrOs_4Sb_(12) and PrRu_4Sb_(12) both as a function of temperature and transverse magnetic field. In a zero magnetic field, the low temperature electronic thermal conductivity of PrRu_4Sb_(12) is consistent with a fully gapped Fermi surface. For PrOs_4Sb_(12), residual electronic conduction in the zero-temperature limit is consistent with the presence of nodes in the superconducting energy gap. The electronic thermal conductivity for both compounds shows a rapid rise at low magnetic fields. In PrRu_4Sb_(12), this is interpreted in terms of multiband effects. In PrOs_4Sb_(12), we consider the Doppler shift of nodal quasiparticles and multiband effects.