Phase-sensitive impurity effects in vortex core of moderately clean chiral superconductors

We study impurity effects in vortex core of two-dimensional moderately clean superconductors within the quasiclassical theory. The impurity scattering rate Gamma>(*) over bar * (E) of the Andreev bound states in vortex core with +1 vorticity of p-wave superconductors with d = (z) over cap (p(x) + ip(y)) is suppressed. compared to the normal state scattering rate Gamma (n) in the energy region Gamma (3)(n)/E-delta(2) much less than E much less than E-delta equivalent to \delta (0)\ Delta (infinity) with scattering phase shift delta (0) (\delta (0)\ much less than 1) and the pair-potential in bulk Delta (infinity). Further we find that Gamma>(*) over bar * (E)/Gamma (n) for p-wave superconductors with d = (z) over cap (p(x) - ip(y)) is at most O(E/Delta (infinity)). These results are in marked contrast to the even-parity case (s,d-wave), where Gamma>(*) over bar * (E)/Gamma (n) is known to be proportional to ln(Delta (infinity)/E). Parity- and chirality-dependences of impurity effects are attributed to the Andreev reflections involved in the impurity-induced scattering between bound states. Implications for the flux flow conductivity is also discussed. Novel enhancement of flux flow conductivity is expected to occur at T much less than E-delta for d = (z) over cap (p(x) + ip(y)) and at T much less than Delta (infinity) for d = (z) over cap (p(x) - ip(y)).