Phase-Sensitive Impurity Effects in Vortex Core of Moderately Clean Chiral Superconductors

We study impurity effects in vortex core of two-dimensional moderately clean su perconductors within the quasiclassical theory. The impurity scattering rate $\text{G}amma(E)$ of the Andreev bound states in vortex core with +1 vorticity of p-wav e superconductors with $\text{mib}d=\widehat{\text{mib}z}(p_x+\text{iu}{p}_y)$ is suppre ssed, compared to the normal state scattering rate ${\mathrm{\Gamma }}_{\mathrm{n}}$ in the energ y region $\Gamma_{\rm n}^3/E_\delta^2\ll E\ll E_\delta\equiv |\delta_0|\Delta_\i nfty$withscatteringphaseshift$\delta_0$ $(\mathrm{\mid }{\delta }_0\mathrm{\mid }\ll 1)$ and the pair-po tential in bulk ${\mathrm{\Delta }}_{\mathrm{\infty }}$. Further we find that $\mathrm{\Gamma }(E)\mathrm{/}{\mathrm{\Gamma }}_{\mathrm{n}}$ for p-wave superconductors with ${\mib d}=\hat{\mib z}(p_x-\iu p_y)$isatmost${\cal O}(E/\Delta_\i nfty)$. These results are in marked contrast to the even-parity case (s,d-wave), where $\mathrm{\Gamma }(E)\mathrm{/}{\mathrm{\Gamma }}_{\mathrm{n}}$ is known to be proportional to $\ln(\Delta_\i nfty/E)$ . Parity- and chirality-dependences of impurity effects are attributed to the Andr eev reflections involved in the impurity-induced scattering between bound states . Implications for the flux flow conductivity is also discussed. Novel enhanceme nt of flux flow conductivity is expected to occur at $T\ll E_\delta$for${\mib d}=\hat{\mib z}(p_x+\iu p_y)$andat$T\ll \Delta_\infty$for${\mib d}=\hat{\mib z}(p_x-\iu p_y)$.