Microscopic theory of spin waves in ferromagnetic stripes and patterned films

A microscopic Hamiltonian-based method is employed to study the dipole-exchange spin waves in ferromagnetic stripes and patterned films. The approach allows studies of spin waves in confined geometries, where the magnetization is inhomogeneous, without using phenomenological boundary conditions. Numerical examples are presented for permalloy stripes with an in-plane magnetic field. The spectrum of discrete spin-wave frequencies is obtained, allowing an interpretation of field-dependent spin reorientations and pinning.