Europhys. Lett.
Volume 70, Number 4, May 2005
Page(s) 513 - 519
Section Condensed matter: electronic structure, electrical, magnetic, and optical properties
Published online 15 April 2005
Europhys. Lett., 70 (4), pp. 513-519 (2005)
DOI: 10.1209/epl/i2004-10511-0

Ferromagnet-superconductor proximity effect: The clean limit

M. Bozovic and Z. Radovic

Department of Physics, University of Belgrade P.O. Box 368, 11001 Belgrade, Serbia and Montenegro

received 30 September 2004; accepted in final form 30 March 2005
published online 15 April 2005

We study theoretically the influence of ferromagnetic metals on a superconducting film in the clean limit. Using a self-consistent solution of the Bogoliubov-de Gennes equation for a ferromagnet-superconductor-ferromagnet double junction, we calculate the pair potential and conductance spectra as a function of the superconducting layer thickness d for different strengths of ferromagnets and interface transparencies. We find that the pair potential and the critical temperature are weakly perturbed by the exchange interaction and do not drop to zero for any finite d. On the other hand, for thin superconducting films charge transport is spin-polarized and exhibits a significant dependence on the ferromagnetic strength and magnetization alignment.

74.45.+c - Proximity effects; Andreev effect; SN and SNS junctions.
74.78.Fk - Multilayers, superlattices, heterostructures.

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