Spin waves in a magnetic stripe submitted to a perpendicular magnetic field

Abstract The static equilibrium magnetization and the spin waves of a magnetic stripe are numerically studied: the calculation is based on a finite element method. The variations of the magnetic properties versus the strength of an in-plane magnetic field applied perpendicularly to the stripe are investigated. Two phase transitions, showing critical fields H 1 and H 2 are evidenced: the first one corresponds to the vanishing of the parallel component of the static magnetization at the center of the section, the second one is defined by the vanishing of this component at the corners of the section. These two phase transitions induce a softening of some eigen frequencies as well as a drastic modification of the profile of the lowest eigen modes.