Magnetoelastic modes in Néel domain walls

Abstract

Spin wave propagation over long distances in confined ferromagnetic strip lines exhibiting magnetoelasticity opens up promising perspectives for device applications. Domain walls as natural spin wave channels increase the spin wave propagation distance. We calculate the magnetic and elastic modes through micromagnetic simulations and the dispersion relation of strip lines containing a Néel wall. We show that at the crossing points in the dispersion relation, two behaviors are observed: an anticrossing gap when a strong coupling is present or a gapless point when the magnetoelastic feedback cycle is not fulfilled. For the Néel wall-confined magnetic mode, the magnetic and elastic waves oscillate independently forming a gapless crossing point. For the domain modes, both behaviors are found. We discuss the gap existence based on the symmetry of the eigenmodes.