POLAR-OPTIC PHONONS AND HIGH-FIELD ELECTRON-TRANSPORT IN CYLINDRICAL GAAS/ALAS QUANTUM WIRES

Linear and nonlinear electron transport in GaAs/AlAs cylindrical quantum wires is investigated with the help of the balance-equation transport theory. Confined phonons, surface phonons, and their Frohlich couplings with electrons in these quasi-one-dimensional electron-phonon systems are described using the dielectric continuum, hydrodynamic continuum, and Huang-Zhu optic-phonon models, respectively. Both intrasubband and intersubband transitions of up to 21 electron subbands are taken into account in the numerical calculation. The comparison of the results from these three models with those obtained by using bulk phonon approximation shows that the bulk phonon approximation is accurate enough to describe the Frohlich interaction when calculating the linear and nonlinear electron transport even in ultrafine GaAs/AlAs quantum wires.