Dynamic exchange coupling in magnetic bilayers
arXiv:cond-mat/0210588 · doi:10.1103/PhysRevLett.90.187601
Abstract
A long-ranged dynamic interaction between ferromagnetic films separated by normal-metal spacers is reported, which is communicated by nonequilibrium spin currents. It is measured by ferromagnetic resonance (FMR) and explained by an adiabatic spin-pump theory. In FMR the spin-pump mechanism of spatially separated magnetic moments leads to an appreciable increase in the FMR line width when the resonance fields are well apart, and results in a dramatic line-width narrowing when the FMR fields approach each other.
5 pages, 3 color figures