Switching smulations in perpendicular media: spin wave instabilities

Summary form only given. Understanding and being able to simulate the mechanism of fast switching is very important for the development of perpendicular recording[ 11. In addition to well-known mechanisms such as curling and domain-wall motion, there has been recent work [2] on a mechanism we will refer to as \´\´spin-wave switching"because it has recently [3] been shown to occur because of a spinwave instability. In this paper we study spin-wave switching in the context of perpendicular recording, using a field history appropriate for a medium (with soft underlayer) passing under a monopolar perpendicular head. We find that the coherent Stoner-Wohlfarth precession is interrupted by a spin-wave instability which causes irreversible switching.