Self consistent order parameter calculations in superconductor-nanowire hybrid systems

Semiconducting nanowire-superconductor hybrid systems provide a promising platform for realizing topological superconductivity that is necessary to host Majorana bound states (MBS). In this study, we employ the Keldsyh nonequilibrium Green's function (NEGF) formalism [1] coupled self consistently with order parameter calculations [2], in order to elucidate the subtleties involved in the issue of current conservation in the N (normal metal)-S (topological superconductor)-N (normal) link. By considering the Kitaev chain as the model system of a topological superconductor, we analyze the transport characteristics pointing out significant variations in the order parameter away from the topological region, and near the topological phase transition point. Our calculations reveal that the bias set up of the N-S-N set up significantly changes the local and non-local contributions to the currents and hence conductances. These results point toward the importance of self consistent evaluation of the order-parameter for accurate and realistic descriptions of the Majorana nanowire set up.
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