Enhanced gilbert damping in thin ferromagnetic films.
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.
Tserkovnyak
Yaroslav
Y
Lyman Laboratory of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
Brataas
Arne
A
Bauer
Gerrit E W
GE