  In the context of polaritons in a ferrite-semiconductor structure which is
influenced by an external static magnetic field, the gyrotropic-nihility can be
identified from the dispersion equation related to bulk polaritons as a
particular extreme state, at which the longitudinal component of the
corresponding constitutive tensor and bulk constant simultaneously acquire
zero. Near the frequency of the gyrotropic-nihility state, the conditions of
branches merging of bulk polaritons, as well as an anomalous dispersion of bulk
and surface polaritons are found and discussed.
