Recent thermal conductivity measurements on UPt3 single crystals by Lussier et al. indicate the existence of a strong b--c anisotropy in the superconducting state. We calculate the thermal conductivity in various unconventional candidate states appropriate for the UPt3 ``B phase" and compare with experiment, specifically the E2u and E1g(1,i) states predicted in some Ginzburg-Landau analyses of the phase diagram. For the simplest realizations of these states over spherical or ellipsoidal Fermi surfaces, the normalized E2u conductivity is found, surprisingly, to be completely isotropic. We discuss the effects of inelastic scattering and realistic Fermi surface anisotropy, and deduce constraints on the symmetry class of the UPt3 ground state.
@article{arxiv.cond-mat/9410087,
title = {Thermal Conductivity Anisotropy in Superconducting $UPt_3$},
author = {A. Fledderjohann and P. J. Hirschfeld},
journal= {arXiv preprint arXiv:cond-mat/9410087},
year = {2009}
}