ABSTRACT
We assume that the excitonic ISB transitions are coupled each other via the effective interaction, which consists of both the electron-electron and electron-LO phonon interactions. Our analysis reveals the importance of ionic screening, which appears in the effective electron-electron interaction. We find that when the matrix element of Coulomb interaction Ln becomes small in single heterojunctions, the effect of ionic screening extremely reduces the light scattering intensity of 1+ peak by the charge-density mechanism because the frequency of 1+ mode approaches coL0.
