Magnetic polaritons in four-sublattice magnetic systems of the GzFx type

Magnetic polaritons in four-sublattice magnetic compounds of the space symmetry D¹⁶_2h with magnetic ordering of the G_zF_x and G_z types, like KMnF₃, RbFeF₃ etc., are considered. Dispersion curves of mixed states of photons and all four magnetic modes are given for some peculiar directions of propagation. The interaction between photons and high-frequency (optic) magnetic modes is shown to be significantly weaker than that between photons and low-frequency spin waves.