Magnon-polaritons and magnetic reststrahlen-bands of uniaxial antiferromagnetic crystals

Abstract The magnitudinal and directional dispersion of the two kinds of magnon-polaritons (magnitons) in uniaxial antiferromagnetic crystals is studied. In particular a proof is given for the existence of a purely longitudinal magnon propagating perpendicular to the optic axis. Furthermore, the corresponding magnetic reststrahlenbands for crystal cuts are discussed.