Quasiparticle Transport in the Vortex State of Unconventional Superconductors

I consider the problem of the vortex contribution to quasiparticle transport in unconventional superconductors with line nodes, a nd argue that the magnetic field dependence of transport coefficients is fixed by the same scattering processes which limit low-temperature transport. I give no detailed calculations, but show that qualitatively correct results may be obtained in the limit of low temperatures and fields by simple physical arguments, based on estimates of the density of states and relaxation time in analogy with the zero-field case. I conclude with a brief discussion of the problem of anisotropy of the field dependence and influence of experimental geometry.