Plasmon-phonon coupling in one-dimensional semiconductor quantum-wire structures

Collective excitation modes of coupled one-dimensional electron- longitudinal-optical-phonon systems (as occurring, for example, in GaAs quantum wires) are calculated in the mean-field approximation. In sharp contrast to higher-dimensional systems, the plasmon-phonon coupling is found to be strong at all densities. We also calculate the inelastic scattering rate of energetic quantum-wire electrons in the random-phase approximation, finding sharp thresholds in the scattering rate corresponding to the emission of coupled plasmon-phonon modes.