  In Ref. [PRL 102, 127202 (2009)] Lee et al. reported the existence of large
magnonic bandgaps in one-dimensional width-modulated Permalloy nanostripe
waveguides based on OOMMF simulations. However, as the symmetry of the magnetic
field pulse they applied to excite the spin waves (SWs) was not general, the
entire set of SW branches with A symmetry was omitted from the magnonic band
structures (see below). This omission has unfortunately led to misleading
conclusions of, for instance, the number, width and position of the bandgaps.
We present here the full band structure based on three different theoretical
approaches that gave consistent predictions, thus corroborating the methods
employed, namely, a microscopic approach, OOMMF simulations, and a method based
on the linearized Landau-Lifshitz equation. Further, we provide a physical
interpretation using group theory.
