Magnetization switching with nonstandard dissipation

We report on our study of magnetization switching in a single-domain ellipsoidal particle. Under the assumption of uniaxial anisotropy collinear with the applied field, we derive an explicit formula for the switching time from the Landau-Lifsehitz equation for a class of dissipation mechanisms that includes Gilbert's, dry friction, and others. While some dissipation is essential to finite-time switching, we show that too much of it would be detrimental, in that it would lengthen the time required to switch, no matter what mechanism is chosen in the class under study.