Phase-Sensitive Flux-Flow resistivity in Unconventional Superconductors

We theoretically investigate the magnetic-field-angle dependence of the flux-flow resistivity rho(f) in unconventional superconductors. Two contributions to rho(f) are considered: one is the quasiparticle (QP) relaxation time tau(k(F)) and the other is omega(0)(k(F)), which is a counterpart to the interlevel spacing of the QP bound states in the quasiclassical approach. Here, k(F) denotes the position on a Fermi surface. Numerical calculations are conducted for a line-node s-wave and a d-wave pair potential with the same anisotropy of their amplitudes, but with a sign change only for a d-wave one. We show that the field-angle dependence of rho(f) differs prominently between s-wave and d-wave pairs, reflecting the phase of the pair potentials. We also discuss the case where tau is constant and compare it with the more general case where tau depends on k(F).