Quasiparticle thermal conductivities in a type-II superconductor at high magnetic fields

We present a calculation of the quasiparticle contribution to the longitudinal thermal conductivities kappa(xx)(H,T) (perpendicular to the external field) and kappa(zz)(H,T) (parallel to the external field) as well as the transverse (Hall) thermal conductivity kappa(xy)(H,T) of an extreme type-II superconductor in a high magnetic field (H-c1<H<H-c2) and at low temperatures. In the limit of frequency and temperature approaching zero (Omega-->0,T-->0), both longitudinal and transverse conductivities upon entering the superconducting state undergo a reduction from their respective normal state values by the factor (Gamma/Delta)(2), which measures the size of the region at the Fermi surface containing gapless quasiparticle excitations. We use our theory to numerically compute the longitudinal transport coefficient in borocarbide and A-15 superconductors. The agreement with recent experimental data on LuNi2B2C is very good.