Interface boundary conditions for dynamic magnetization and spin wave dynamics in a ferromagnetic layer with the interface Dzyaloshinskii-Moriya interaction

摘要

In this work we derive the interface exchange boundary conditions for theclassical linear dynamics of magnetization in ferromagnetic layers with theinterface Dzyaloshinskii-Moriya interaction (IDMI). We show that IDMI leads topinning of dynamic magnetization at the interface. An unusual peculiarity ofthe IDMI-based pinning is that its scales as the spin-wave wave number. Weincorporate these boundary conditions into an existing numerical model for thedynamics of the Damon-Eshbach spin wave in ferromagnetic films. IDMI affectsthe dispersion and the frequency non-reciprocity of the traveling Damon-Eshbachspin wave. For a broad range of film thicknesses L and wave numbers the resultsof the numerical simulations of the spin wave dispersion are in a goodagreement with a simple analytical expression which shows that the contributionof IDMI to the dispersion scales as 1/L, similarly to the effect of other typesof interfacial anisotropy. Suggestions to experimentalists how to detect thepresence of IDMI in a spin wave experiment are given.