Localization of Acoustical Modes Due to the Electron-Phonon Interaction Within a Two-Dimensional Electron Gas

Abstract

The authors study the localization of acoustical modes within a two-dimensional electron gas (2DEG) due to only the electron-phonon interaction. The localized modes split out from the bulk phonons even at uniform lattice parameters, when the 2DEG is created by means of modulation doping, for example under delta -doping. The effect is more pronounced when the wave vector q of the modes increases and is maximum at q=2kF (kF is the Fermi wave vector). In the case of several electron sheets the additional feature of the localization effect appear.