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# Secondary "Smile"-gap in the density of states of a diffusive Josephson junction for a wide range of contact types

Type of Publication: | Preprint |

URI (citable link): | http://nbn-resolving.de/urn:nbn:de:bsz:352-282166 |

Author: | Reutlinger, Johannes; Glazman, Leonid; Nazarov, Yuli V.; Belzig, Wolfgang |

Year of publication: | 2014 |

ArXiv-ID: | arXiv:1406.6797 |

Summary: |
The superconducting proximity effect leads to strong modifications of the local density of states in diffusive or chaotic cavity Josephson junctions, which displays a phase-dependent energy gap around the Fermi energy. The so-called minigap of the order of the Thouless energy E
_{Th} is related to the inverse dwell time in the diffusive region in the limit E_{Th} << delta, where delta is the superconducting energy gap. In the opposite limit of a large Thouless energy E_{Th} >> delta a small new feature has recently attracted attention, namely the appearance of a further secondary gap, which is around two orders of magnitude smaller compared to the usual superconducting gap. It appears in a chaotic cavity just below the superconducting gap edge delta and vanishes for some value of the phase difference between the superconductors. We extend previous theory restricted to a normal cavity connected to two superconductors through ballistic contacts to a wider range of contact types. We show that the existence of the secondary gap is not limited to ballistic contacts, but is a more general property of such systems. Furthermore we derive a criterion which directly relates the existence of a secondary gap to the presence of small transmission eigenvalues of the contacts. For generic continuous distributions of transmission eigenvalues of the contacts no secondary gap exists, although we observe a singular behavior of the density of states at delta. Finally we provide a simple one-dimensional scattering model which is able to explain the characteristic "smile" shape of the secondary gap. |

Subject (DDC): | 530 Physics |

Link to License: | Terms of use |

Bibliography of Konstanz: | Yes |

Checksum:
MD5:88d316068094e07de4e3a40cbfd72aa5

REUTLINGER, Johannes, Leonid GLAZMAN, Yuli V. NAZAROV, Wolfgang BELZIG, 2014. Secondary "Smile"-gap in the density of states of a diffusive Josephson junction for a wide range of contact types

@unpublished{Reutlinger2014Secon-28216, title={Secondary "Smile"-gap in the density of states of a diffusive Josephson junction for a wide range of contact types}, year={2014}, author={Reutlinger, Johannes and Glazman, Leonid and Nazarov, Yuli V. and Belzig, Wolfgang} }

Reutlinger_282166.pdf | 128 |