Author/Authors :
Pusep، نويسنده , , Yu.A. and da Silva، نويسنده , , S.W. and Galzerani، نويسنده , , J.C. and Lubyshev، نويسنده , , D.I. and Basmaji، نويسنده , , P. and Milekhin، نويسنده , , A.G. and Preobrazhenskii، نويسنده , , V.V. and Semyagin، نويسنده , , B.R. and Marahovka، نويسنده , , I.I.، نويسنده ,
Abstract :
We present a new interpretation of the Raman spectra of GaAs/AlAs ultrathin-layer superlattices based on the microscopic analysis of the optical vibrational modes. The difference between normal and inverted interfaces is responsible for the lack of the inversion symmetry of the layers with respect to the central plane, therefore confined modes can no longer be considered as even or odd ones. All the optical vibrational modes, independently of their quantum index, are now active in Raman scattering.