What Does the Field Dependence of the Thermal Conductivity of the Heavy Fermion SuperconductorUPt3Tell Us about the Symmetry of the Order Parameter?

Abstract

We investigate the field dependence of the thermal conductivity {kappa} of UPt{sub 3} single crystals for magnetic fields applied along the basal ({ital ab}) plane and along the {ital c} axis, respectively. The effect of heat carrying electrons scattered by quasiparticle excitations in the vortex cores is calculated for an anisotropic superconducting gap parameter of either E{sub 1g} or E{sub 2u} symmetry. It is shown that the anisotropy of the field dependence of {kappa} allows one to probe the symmetry of the superconducting order parameter and favors the E{sub 2u} gap parameter, i.e., with quadratic point nodes along the {ital c} axis. {copyright} {ital 1997} {ital The American Physical Society}