Quasi-one-dimensional polaron gas in a GaAs quantum wire
In this work we present a study of the plasmon-longitudinal-optical (LO) phonon collective excitation as a function of the quasi-one-dimensional wave vector for several electronic densities and thickness of the wires. We observed that the intra- and intersubband excitation collective energies are very sensitive to electronic density variation. This effect is more pronounced for the lower branch of the collective excitation energy and for narrower wires. Our calculations are performed using the Singwi, Tosi, Land and Sjolander (STLS) theory, at zero temperature, assuming a three-subband model, where only the first subband is occupied by electrons.
Plasmon-phonon coupling in one-dimensional semiconductor quantum-wire structures.
Collective excitation modes of coupled one-dimensional electron\char21{}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.
Position-dependence of the impurity binding energy in quantum well wires
Abstract We present the results of variational calculations of the binding energy of hydrogenic impurities in quantum well wires with rectangular cross-section. The emphasis is placed on the dependence of the binding energy on the size of the wire cross section and on the positions of the impurity. The impurity binding energy decreases when the impurity position changes from the center of the wire to its edge or to one of the corners of the rectangular cross section.