2004/06/11 by R. Mélin, Mélin, R.
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #Superconductivity (cond-mat.supr-con) #Superconductivity in MgB2 and Alloys #cond-mat.mes-hall #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.cond-mat/0406280
4 pages, 1 figure. To appear in the proceedings of the XXXIX Rencontres de Moriond (La Thuile, 2004)
arxiv created 2004/06/11 · openalex publication_date 2004/06/11 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We contrast perturbative expansions of ferromagnet / superconductor interfaces in two geometries: (i) a point contact geometry where a single weak link connects a 3D ferromagnet to a 3D superconductor and (ii) an atomic thickness geometry with an infinite planar interface connecting a quasi-2D ferromagnet to a quasi-2D superconductor. Perturbation theories are rather different in the two approaches but they both break down at order t4 (t is the tunnel amplitude). The regimes of strong ferromagnets are in a qualitative agreement in both geometries. The regime of weak ferromagnets exists only for the atomic thickness geometry and is related to Andreev bound states due to lateral confinement in the superconductor.