Nonreciprocal Optical Reflection of the Uniaxial Antiferromagnet MnF2

Abstract
Microwave reflectivity measurements in Voigt geometry were performed on a polished surface of MnF2. We observed nonreciprocal behavior in the reflectivity with respect to the magnetic field reversal. The nonreciprocal behavior of the antiferromagnet's reflectivity gives clear evidence for the existence of nonreciprocal dipolar antiferromagnetic surface spin-wave excitations. The results are quantitatively explained. They give very accurate values for antiferromagnetic resonance and spin-wave damping.