Abstract:
We consider the proximity effect in multiterminal ferromagnet/superconductor (FSF) hybrid structures in which two or three electrodes are connected to a superconductor. We show that two competing effects take place in these systems: (i) pair breaking effects due to the response to the exchange field induced in the superconductor; (ii) a reduction of the superconducting order parameter at the interface that takes place already in NS junctions. We focus on this second effect that dominates if the thickness of the S layer is small enough. We consider several single-channel electrodes connected to the same site. We calculate the superconducting order parameter and the local density of state (LDOS). With two ferromagnetic electrodes connected to a superconductor we find that the superconducting order parameter in the ferromagnetic alignment is larger than the superconducting order parameter in the antiferromagnetic alignment ( > ), in agreement with [Eur. Phys. J. B 25, 373 (2002)]. If a third spin polarized electrode is connected to a superconductor we find that - can change sign as the transparency of the third electrode increases. This can be understood from the fact that the superconducting order parameter is reduced if pair correlations among the ferromagnetic electrodes increase. If the two ferromagnetic electrodes are within a finite distance we find Friedel oscillations in the Gorkov function but we still obtain > .
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received 6 May 2002 / Received in final form 20 November 2002 Published online 27 January 2003
RID="a"
ID="a"e-mail: melin@grenoble.cnrs.fr
RID="b"
ID="b"UPR 5001 du CNRS, Laboratoire conventionné avec l'Université Joseph Fourier
Rights and permissions
About this article
Cite this article
Jirari, H., Mélin, R. & Stefanakis, N. Proximity effect in multiterminal hybrid structures. Eur. Phys. J. B 31, 125–139 (2003). https://doi.org/10.1140/epjb/e2003-00016-8
Issue Date:
DOI: https://doi.org/10.1140/epjb/e2003-00016-8