Effect of impurities and random pinning on the superconducting vortex state

Abstract

The presence of impurities affects the quasiparticles via potential scattering and pinning of the vortices. We calculate self-consistently the local density of states of an inhomogeneous superconductor in a magnetic field with a random distribution of impurities. The quasiparticles are only significantly affected by the impurities in their vicinity. In contrast, the random distribution of vortices increases the density of states at low energies by filling the gap in the s-wave case and creating a finite value in the d-wave case. The dominant effect on the quasiparticles is due to the vortex scattering.