Influence of the screening model and wave-function shape on impurity scattering mobility in quantum wire

Abstract

Articles you may be interested inResonant tunneling field-effect transistor based on wave function shape modulation in quantum wires Impurity scattering limited mobility in a quantum well heterojunction J.A theoretical investigation of impurity scattering limited mobility in a quantum wire is presented. The general method of mobility calculation is presented and some approximations are made in order to simplify the.problem and reduce the amount of computations. Cylindrical symmetry of the wire is assumed and the carriers are assumed to be confined by an in&rite barrier. The mobility has been computed using the exact wave functions and the results are compared with those obtained using constant or Dirac wave-function approximations. It is shown that the mobility is strongly influenced by the shape of the wave function. The screening effect is introduced using two different models. At high temperatures both models yield similar results whereas at low temperature a significant discrepancy is observed. The influence of important parameters such as wire dimension, carrier density, and temperature on impurity scattering mobility is investigated. A comparison of impurity scattering mobility in quantum well and quantum wire is also presented. Finally, it is shown that the electron-transport properties in quantum wires may be strongly enhanced by the use of a large spacer.

Electron–impurity scattering in free-standing quantum wires: Effect of dielectric confinement

“…Finally, the mobility dependence on N imp and L sp shows the well-known trends, previously discussed for buried GaAs wires of cylindrical symmetry. 9,12,13 Figure 4 shows the same calculation as Fig. 3, but for the lattice temperature of 77 K. The obtained mobilities are qualitatively similar to those in Fig.…”

“…Full ͑empty͒ circles show the screened ͑unscreened͒ results taken fromFig. 8of Ref 9. for the cylindrical wire of the same cross section area.…”

Impurity-Scattering Limited Electron Mobility in Free Standing Quantum Wires: Image Charge Effect

“…1. The mobility dependence on Nimp and Lsp shows the well-known trends, previously discussed for buried GaAs wires [3][4][5]. Figure 2 shows the same calculation as Fig.…”

Electron Spin Relaxation in GaAs/AlGaAs Quantum Wires Analyzed by Transient Photoluminescence

“…On the other hand, because of the strong confinement in the quantum wire, the phonon interaction limiting the mobility is suppressed. Moreover, assuming contributions of other temperature-dependent scatterings such as that due to impurities, 18) the temperature dependence of the momentum relaxation time is expected to compensate the above-mentioned positive power decrease. Thus, overall temperature dependence of the spin relaxation rate may positively become stronger for quantum wires than for quantum wells, which corresponds to the observation in the present experiment.…”