Raman scattering in GaAs/AlAs structures with paired quantum wells
Gaisler V. A. , Tenne D. A. , Govorov A. O. , Moshegov N. T. , Toropov A. I. , Shebanin A. P.
Both nonresonant and resonant Raman scattering of light by longitudinal optical phonons have been studied in GaAs/AlAs structures with paired quantum wells. Because of the particular shape of the envelopes of the electron wave functions and potentials set up by the phonons, it was found possible, for the first time, to observe a scattering by odd and even localized LO phonons simultaneously under nonresonant conditions. The absence of peaks corresponding to odd phonons from the Raman scattering spectrum is explained on the basis of an additional scattering mechanism: a Frohlich interaction which is induced by defects and which leads to the predominance of even modes in the spectra.