Surface Phonons in Superlattices
Résumé
We report the existence of surface localized phonons for a superlattice consisting of alternating slabs (parallel to the surface) of two different crystals. The superlattice has a larger periodicity in the direction perpendicular to the slabs and therefore many phonon branches in the folded Brillouin zone. In the gaps existing between these phonon branches appear the surface localized modes.