Phonon-Drag Images of GaAs and AlAs Quantum Wells

In the presented (first) study we analyze the changes in the phonon-drag patterns of AlAs and GaAs quantum wells as a function of well thickness. Our numerical calculations include the phonon focusing, the acoustic anisotropy of the electron-phonon coupling and the conduction-band anisotropy. From such analysis, in connection with future systematic experimental studies, one can draw information about the electron-phonon coupling parameters and the effective mass of the electrons. A domination of electron-phonon interaction by deformation potential coupling in narrow AlAs quantum wells is shown. A comparison of our numerical results with recent phonon-drag measurements of an AlAs quantum well shows very good agreement.