Induced ferromagnetism due to superconductivity in superconductor-ferromagnet structures

We consider a superconductor-ferromagnet ~S/F! structure and assume that above the superconducting transition temperature Tc the magnetic moment exists only in F. In a simple model of the ferromagnet (the exchange field is of the ferromagnetic type for all energies) we show by an explicit calculatio...

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Detalles Bibliográficos
Autores: Bergeret, F. Sebastian, Volkov, Anatoly F., Efetov, K. B.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2004
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/224893
Acceso en línea:http://hdl.handle.net/10261/224893
Access Level:acceso abierto
Descripción
Sumario:We consider a superconductor-ferromagnet ~S/F! structure and assume that above the superconducting transition temperature Tc the magnetic moment exists only in F. In a simple model of the ferromagnet (the exchange field is of the ferromagnetic type for all energies) we show by an explicit calculation that below Tc the magnetic moment may penetrate the superconductor. In this model its direction in S is opposite to the magnetization of free electrons in the ferromagnet. The magnetization spreads over a large distance which is of the order of the superconducting coherence length €S and can much exceed the ferromagnet film thickness. At the same time the magnetic moment in the ferromagnet is reduced. This inverse proximity effect may explain the reduction in magnetization observed in recent experiments and may lead to a strong interaction between the ferromagnetic layers in F/S/F structures.