Nonreciprocal reflection of infrared radiation from structures with antiferromagnets and dielectrics

We calculate the reflectivity from structures involving both dielectric and antiferromagnetic films. In contrast to earlier results involving only antiferromagnetic films, we find that nonreciprocal reflection occurs even in the absence of any absorption. The calculations are done with a transfer matrix method and examples of nonreciprocal reflectivity are shown both with and without,damping, In addition a general thermodynamic argument is presented which shows why nonreciprocity is allowed for the structure involving both dielectrics and antiferromagnets while it is forbidden for a simple antiferromagnetic film. The thermodynamic argument also gives some symmetry relations shown in our explicit calculations.