Low-frequency dynamics in an antiferromagnetic superlattice

We present a theoretical study of the surface spin-flop transition which oc curs in Fe/Cr multilayer films. The low-frequency response is effectively r educed to the dynamics of an antiferromagnetic discrete sine-Gordon equatio n due to the strong demagnetizing field created by out-of-plane fluctuation s. We thus carry out a detailed calculation of dynamic susceptibilities whi ch confirms and completes earlier theoretical work, and may suggest further experimental investigation of some of the more intricate aspects of this s ubject.