  We identify different types of the photonic band gaps (PBGs) of two
dimensional magnetic photonic crystals (MPCs) consisting of arrays of magnetic
cylinders and study the different tunability (by an external static magnetic
field) of these PBGs. One type of the band gaps comes from infinitely
degenerate flat bands and is closely related to those in the study of
plasmonics. In addition, such PBGs are magnetically tunable and robust against
position disorder. We calcualte the transmission of the PBG's and found
excellent agreement with the results of the photonic band structure
calculation. Positional disorder of the lattice structure affects the different
types of PBGs differently.
