{ "id": "1510.03834", "version": "v1", "published": "2015-10-13T19:37:07.000Z", "updated": "2015-10-13T19:37:07.000Z", "title": "Josephson current between topological and conventional superconductors", "authors": [ "P. A. Ioselevich", "P. M. Ostrovsky", "M. V. Feigelman" ], "comment": "7 pages, 2 figures", "categories": [ "cond-mat.mes-hall" ], "abstract": "We study the stationary Josephson current in a junction between a topological and an ordinary (topologically trivial) superconductor. Such an S-TS junction hosts a Majorana zero mode that significantly influences the current-phase relation. The presence of the Majorana state is intimately related with the breaking of the time-reversal symmetry in the system. We derive a general expression for the supercurrent for a class of short topological junctions in terms of the normal state scattering matrix. The result is strongly asymmetric with respect to the superconducting gaps in the ordinary ($\\Delta_0$) and topological ($\\Delta_{\\mathrm{top}}$) leads. We apply the general result to a simple model of a nanowire setup with strong spin-orbit coupling in an external magnetic field and proximity-induced superconductivity. The system shows parametrically strong suppression of the critical current $I_c \\propto \\Delta_{\\mathrm{top}}/R_N^2$ in the tunneling limit ($R_N$ is the normal state resistance). This is in strong contrast with the Ambegaokar-Baratoff relation applicable to junctions with preserved time-reversal symmetry. We also consider the case of a generic junction with a random scattering matrix and obtain a more conventional scaling law $I_c \\propto \\Delta_{\\mathrm{top}}/R_N$.", "revisions": [ { "version": "v1", "updated": "2015-10-13T19:37:07.000Z" } ], "analyses": { "keywords": [ "conventional superconductors", "topological", "time-reversal symmetry", "normal state resistance", "normal state scattering matrix" ], "note": { "typesetting": "TeX", "pages": 7, "language": "en", "license": "arXiv", "status": "editable" } } }