title: Josephson junction through a thin ferromagnetic layer: negative coupling.
abstract: We investigate Josephson coupling through a ferromagnetic thin film using superconductor-insulator-ferromagnet-superconductor planar junctions. Damped oscillations of the critical current are observed as a function of the ferromagnetic layer thickness. We show that they result from the exchange energy gained or lost by a quasiparticle Andreev-reflected at the ferromagnet-superconductor interface. The critical current cancels out at the transition from positive ("0") to negative ("pi") coupling, in agreement with theoretical calculations.
authors.affiliation: CSNSM-CNRS, Université Paris-Sud, 91405 Orsay Cedex, France.
authors.forename: T
authors.initials: T
authors.lastname: Kontos
authors.forename: M
authors.initials: M
authors.lastname: Aprili
authors.forename: J
authors.initials: J
authors.lastname: Lesueur
authors.forename: F
authors.initials: F
authors.lastname: Genêt
authors.forename: B
authors.initials: B
authors.lastname: Stephanidis
authors.forename: R
authors.initials: R
authors.lastname: Boursier