Nonmonotonous magnetic field dependence and scaling of the thermal conductivity for superconductors with nodes of the order parameter

We show that there is a new mechanism for nonmonotonous behavior of magnetic field dependence of the electronic thermal conductivity κ of clean superconductors with nodes of the order parameter on the Fermi surface. In particular, for unitary scatterers the nonmonotony of relaxation time takes place. Contribution from the intervortex space turns out to be essential for this effect even at low temperatures. Our results are in a qualitative agreement with recent experimental data for superconductingUPt3 [1,2]. For E2u-type of pairing we find approximately the scaling of the thermal conductivity in clean limit with a single parameter x = T Tc √ Bc2 B at low fields and low temperatures, as well as weak low-temperature dependence of the anisotropy ratio κzz/κyy in zero field. For E1g-type of pairing deviations from the scaling are more noticeable and the anisotropy ratio is essentially temperature dependent. PACS numbers: 74.25.Fy, 74.70.Tx Typeset using REVTEX 1