Experimental determination of magnetic polariton dispersion curves inFeF2

Abstract
A series of high-resolution attenuated total reflection and reflectivity measurements in the far infrared are used to obtain experimental dispersion curves for bulk and surface magnetic polaritons in uniaxial antiferromagnets. In addition to bulk and surface modes, the individual spectra also allow identification of, to the best of our knowledge, previously unseen surface resonances. The spectra also show huge nonreciprocity in infrared reflectivity at low fields, a feature unique to magnetic systems.