Using the highly inhomogeneous fields of a magnetic substrate, tunablejunctions between superconducting and normal state regions were created insidea thin film superconductor. The investigation of these junctions, created inthe same material, gave evidence for the occurrence of Andreev reflection,indicating the high transparency of interfaces between superconducting andnormal state regions. For the realization of this study, a ferromagnet withmagnetic stripe domains was used as a substrate, on top of which asuperconducting transport bridge was prepared perpendicular to the underlyingdomains. The particular choice of materials allowed to restrict the nucleationof superconductivity to regions above either reverse-domains or domain walls.Moreover, due to the specific design of the sample, transport currents in thesuperconductor passed through a sequence of normal and superconducting regions.
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