Fast magnetization switching of Stoner particles: A nonlinear dynamics picture

摘要: The magnetization reversal of Stoner particles is investigated from the point view nonlinear dynamics within Landau-Lifshitz-Gilbert formulation. following results are obtained. 1) We clarify that so-called Stoner-Wohlfarth (SW) limit becomes exact when damping constant infinitely large. Under limit, moves along steepest energy descent path. minimal switching field one at which there only stable fixed in system. 2) For a given magnetic anisotropy, critical value for constant, above same as SW-limit. 3) illustrate how points and their basins change under different directions. This explains well why non-parallel gives smaller short time. 4) ballistic should be certain direction window presence dissipation. width depends on both anisotropy. upper lower bounds increase with constant. oscillates It zero infinite damping. Thus, perpendicular configuration widely employed current experiments not best since real system far zero.