Tuesday, October 9, 2012

1210.1875 (Stanislav Apostolov et al.)

Josephson current and density of states in proximity circuits with s+-
superconductors
   [PDF]

Stanislav Apostolov, Alex Levchenko
We study the emergent proximity effect in mesoscopic circuits which involve conventional superconductor and unconventional pnictide superconductor separated by a diffusive normal or ferromagnetic wire. The focus is placed on revealing signatures of the proposed s+- state of pnictides from the proximity-induced density of states and Josephson current. We find analytically a universal result for the density of states which exhibits both a Thouless gap at low energies, and peculiar features near the superconducting gap edges at higher energies. The latter may be used to discriminate between s+- and s++ symmetry scenarios in scanning tunneling spectroscopy experiments. We also calculate Josephson current-phase relationships for different junction configurations, which are found to display robust 0-\pi transitions for a wide range of parameters.
View original: http://arxiv.org/abs/1210.1875

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