2001/06/08 by Branislav K. Nikolic, Branislav K. Nikolić, J. K. Freericks +2
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.65.064529
published as Phys. Rev. B 65, 064529 (2002). · 15 pages, 15 EPS embedded figures
arxiv created 2001/06/08 · openalex publication_date 2002/01/23 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We report on a self-consistent microscopic study of the dc Josephson effect in SINIS junctions, where screened dipole layers at the SN interfaces generate a double-barrier multilayered SIN structure. Our approach starts from a microscopic Hamiltonian defined on a simple cubic lattice, with an attractive Hubbard term accounting for the short coherence length superconducting order in the semi-infinite leads, and a spatially extended charge distribution (screened dipole layer) induced by the difference in Fermi energies of the superconductor S and the clean normal metal interlayer N. We analyze the influence of such spatially inhomogeneous barriers on the proximity effect, the current-phase relations, the critical supercurrent and the normal-state junction resistance, for different normal interlayer thicknesses and barrier heights. These results are of relevance for high-Tc grain boundary junctions, and also reveal one of the mechanisms that can lead to low critical currents of apparently ballistic SNS junctions while increasing its normal-state resistance in a much weaker fashion. When the N region is a doped semiconductor, we find a substantial change in the dipole layer (generated by a small Fermi-level mismatch) upon crossing the superconducting critical temperature, which is a signature of the proximity effect and which might be related to recent Raman studies in Nb/InAs bilayers.