High-field electron transport in quantum wires studied by solution of the Boltzmann equation

High-field electron transport properties in a one-dimensional GaAs quantum wire are studied by a novel method to solve numerically the Boltzmann equation with Fermi-Dirac statistics. The wire is so narrow that quantum subbands are formed. Impurity scattering, optical-phonon scattering, and intersubband scattering are considered in the model. It is shown that two types of electron transport take place, depending on the electron line density and the electric field strength: (1) Electrons are confined to the energy region below the optical-phonon energy {Δ} under strong optical-phonon scattering around {Δ}, and (2) they exhibit velocity runaway in the energy region above {Δ} under decreasing optical-phonon scattering with increasing electron energy.