ar X iv : c on d - m at / 9 41 00 14 v 1 6 O ct 1 99 4 Andreev reflection in ferromagnet – superconductor junctions
نویسنده
چکیده
The transport properties of a ferromagnet–superconductor (FS) junction are studied in a scattering formulation. Andreev reflection at the FS interface is strongly affected by the exchange interaction in the ferromagnet. The conductance GFS of a ballistic point contact between F and S can be both larger or smaller than the value GFN with the superconductor in the normal state, depending on the ratio of the exchange and Fermi energies. If the ferromagnet contains a tunnel barrier (I), the conductanceGFIFS exhibits resonances which do not vanish in linear response — in contrast to the Tomasch oscillations for non-ferromagnetic materials. PACS numbers: 74.80.Fp, 72.10.Bg, 74.50.+r Typeset using REVTEX
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