Raman scattering from GaSb/AlSb superlattices: Acoustic, optical, and interface vibrational modes

We report a detailed Raman study of folded acoustic phonons, confined optical phonons, and interface vibrational modes in GaSb/AlSb superlattices grown on [001]-oriented GaSb substrates. A number of unusual features are observed in the intensity dependence of the Raman lines on the incident laser energy, for laser excitations ranging from the electronic transition energies $E_1$ of GaSb to $E_0$ of AlSb.