The localized interface optical-phonon modes lying in a mini-gap of AlAs-GaAs superlattice with structural defects consisting of ternary mixed-crystal AlxGa1-xAs were studied in the dielectric continuum approximation. It was found that three localized interface optical modes appeared in each frequency mini-gap for certain structural parameters. Two of them were anti-symmetrical with respect to the center of the defect layers and display interesting features significantly different from those in the structure with a binary crystal defect layer. However, the third mode with symmetric property showed similar behavior as that in the structure with a binary crystal defect layer.

Effect of Structural Defects Consisting of Ternary Mixed Crystals on Localized Interface Optical Modes in Superlattices. K.Q.Chen, X.H.Wang, B.Y.Gu: Physical Review B, 2002, 65[15], 153305 (4pp)