Nonreciprocal magnetic photonic crystals

We study band dispersion relations omega((k) over right arrow) of a photonic crystal with at least one of the constitutive components being a magnetically ordered material. It is shown that by proper spatial arrangement of magnetic and dielectric components one can construct a magnetic photonic crystal with strong spectral asymmetry (nonreciprocity) omega((k) over right arrow)not equal omega(-(k) over right arrow). The spectral asymmetry, in turn, results in a number of interesting phenomena, in particular, one-way transparency when the magnetic photonic crystal, being perfectly transparent for a Bloch wave of frequency Omega, freezes the radiation of the same frequency Omega propagating in the opposite direction. The frozen radiation corresponds to a Bloch wave with zero group velocity partial derivative omega (k)partial derivativek=0 and, in addition, with partial derivative (2)omega (k)/partial derivativek(2) = 0.