On FMR modes in bubble domain lattices

Two solutions of the problem of non-uniform ferromagnetic resonance in a hexagonal bubble domain lattice are presented under the simplifying assumption of lattice period much smaller than the film thickness. Fine divisions of the lattice cell into supposedly uniform subdomains render sets of linear equations for the local amplitudes which are solved numerically. Analytical solution of the time-dependent magnetostatic (Walker-mode) problem is obtained by expansion in simple elliptic functions similar to that suggested by Sigal. The results support, respectively, the interpretation of FMR experiments derived by Klem and Kaczér from a crude (minimal) subdivision of the elementary cell, and the three-mode dipolar-field model recently proposed by the author on a largely intuitive basis.