DYNAMICAL SCREENING EFFECTS IN A COUPLED QUASI-ONE-DIMENSIONAL ELECTRON-PHONON SYSTEM

A fully dynamical and finite-temperature study of the electron momentu m relaxation rate and mean free path in a coupled system of electrons and bulk LO phonons in a quantum wire structure is presented. Electron -electron and electron-phonon interactions are treated on an equal foo ting within the leading-order perturbation theory and random-phase app roximation. It is demonstrated that coupled-mode effects drastically c hange the transport properties of the system at low temperatures. In p articular, the 'plasmon-like' and 'LO-phonon-like' excitations yield c omparable rates which, as a consequence of the singular nature of the 1D density of states, can be large at the threshold. This is in contra st to room temperature results where only the LO-phonon mode contribut es significantly to the rate.