Formation of robust and completely tunable resonant photonic band gaps

We examine the mechanism governing the photonic band gaps (PBGs) in two-dimensional magnetic photonic crystals consisting of ferrite cylinders, based on the simulation on the band structure and the transmission spectra. Besides the conventional PBG resulting from the Bragg scattering, two other types of PBGs, owing, respectively, to the Mie scattering resonance and the spin-wave resonance, are identified. Of particular interest is the PBG due to the Mie resonance that can be regarded as a magnetic analog of the surface plasmon in metal. The ``magnetic surface plasmon'' induced resonant PBGs is shown to be completely tunable by an external static magnetic field and robust against position disorder of the ferrite rods, in addition to possessing an analytically predictable PBG frequency.