On giant amplification of effects of phonon nonspecular reflection at a solitary interface between magnetic and non-magnetic media

On the secluded interface of semi-infinite magnetic and non-magnetic media, hybridiza-tion of magnetoelastic interaction with inhomogeneous exchange or magneto-dipole interaction can lead to the formation of symmetry-protected bound states in the radiation spectrum of the leaky surface magnon polarons. If a quasi-plane bulk elastic wave falls on the surface of a magnetic medium from outside, and the wave parameters approach to the parameters of the surface “dark” state of the above mentioned type, the nonspecular reflection effects of the first order increase unrestrictedly (in the non-dissipative approximation).