Raman scattering from InAs/AlSb ultrathin-layer superlattices grown by molecular beam epitaxy

Abstract Experimental analysis by Raman scattering has been performed to study characteristics phonon modes in InAs/AlSb ultrathin-layer superlattices (ULS's) grown by molecular beam epitaxy. Zone-folded longitudinal acoustic and confined optical phonons have been observed in the Raman spectra of these ULS's. In addition to them, we have observed new phonon modes localized at the heterointerface for the first time. It is also shown that the excitation of localized modes depends on the types of interface bonds, InSb- or AlAs-like, formed in the ULS's.