Andreev levels in anisotropic S-N-S junctions

In this work we investigate the effect of different symmetries of the pair potential on the quasiparticle energy levels in SNS superconducting weak links (S: superconductor, N: metal in the normal state). The energy levels are affected by the phase difference between the two superconducting regions. In particular we study the junctions Ss-N-Ss, Ss-N-Sd and Sd-N-Sd, where the subscripts mean s- and d-symmetry. We take into account the situations in which s is an isotropic, anisotropic or extended s-symmetry. (orig.)