Electron mobility in a GaAs/AlAs quantum well with a thin AlAs middle barrier

We report a theoretical investigation of optical phonon modes in GaAs/AlAs double quantum wells using the dielectric continuum model. The phonon modes in the narrow and the wide limits for the widths of an inserted AlAs layer are discussed and compared with those in GaAs/AlAs single wells. The corresponding Fröhlich interaction matrix elements are obtained and the intrasubband and intersubband electron-phonon interactions are studied. Employing the force balance equation, we calculated the electron mobility from the dielectric continuum model and from the bulk phonon approximation. The possibility of the enhancement of the electron mobility in this double-well structure is discussed.