DYNAMICAL SCREENING EFFECTS IN HOT-ELECTRON SCATTERING FROM ELECTRON-HOLE PLASMA AND LO-PHONON MODES IN QUANTUM WIRES

We present a fully dynamical and finite temperature study of the hot-e lectron momentum relaxation rate and the power loss in a coupled syste m of electron-hole plasma and bulk LO-phonons in a quantum wire struct ure. Interactions of the scattered electron with neutral plasma compon ents and phonons are treated on an equal footing within the random-pha se approximation. Coupled mode effects substantially change the transp ort properties of the system at low temperatures. Particularly, the '' plasmon-like'' and ''LO-phonon-like'' excitations yield comparable rat es which, as a consequence of the singular nature of the 1D density of states, can be large at the threshold. This is in contrast to room te mperature results where only the LO-phonon mode contributes significan tly to the rate. The density and temperature dependence of the power l oss reveals that dynamical screening effects are important, and energy -momentum conservation cannot be satisfied above a certain density for a given initial energy. Copyright (C) 1996 Elsevier Science Ltd