title: Enhanced gilbert damping in thin ferromagnetic films.
abstract: The precession of the magnetization of a ferromagnet is shown to transfer spins into adjacent normal metal layers. This "pumping" of spins slows down the precession corresponding to an enhanced Gilbert damping constant in the Landau-Lifshitz equation. The damping is expressed in terms of the scattering matrix of the ferromagnetic layer, which is accessible to model and first-principles calculations. Our estimates for permalloy thin films explain the trends observed in recent experiments.
authors.affiliation: Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Yaroslav
authors.initials: Y
authors.lastname: Tserkovnyak
authors.forename: Arne
authors.initials: A
authors.lastname: Brataas
authors.forename: Gerrit E W
authors.initials: GE
authors.lastname: Bauer