NONRECIPROCAL REFLECTION OF INFRARED RADIATION FROM STRUCTURES WITH ANTIFERROMAGNETS AND DIELECTRICS

We calculate the reflectivity from structures involving both dielectri c and antiferromagnetic films. In contrast to earlier results involvin g only antiferromagnetic films, we find that nonreciprocal reflection occurs even in the absence of any absorption. The calculations are don e with a transfer matrix method and examples of nonreciprocal reflecti vity are shown both with and without,damping, In addition a general th ermodynamic argument is presented which shows why nonreciprocity is al lowed for the structure involving both dielectrics and antiferromagnet s while it is forbidden for a simple antiferromagnetic film. The therm odynamic argument also gives some symmetry relations shown in our expl icit calculations.