Quantum-mechanical simulation of electron waveguides in linear and nonlinear transport regimes

The linear and nonlinear quantum transport in an electron waveguide is simulated using the Wigner function model. In the linear transport regime, the effects of impurity scattering on the quantized conductance of the electron waveguide are studied in detail. The decrease of conductance and the deterioration of quantized steps due to impurity scattering are found to become more conspicuous as the impurity density increases. When the impurity density increases much more, the quantized steps of conductance disappear to approach the conductance values estimated by the classical model. In the nonlinear transport regime at large bias voltage, the current-voltage characteristics of the electron waveguide are studied at T=0 and 300 K. It is found that the conductance of the electron waveguide at low temperature deviates from the quantized value of 2e/sup 2//h as the bias voltage increases. The possibility of the transistor operation of the electron waveguide at room temperature is discussed.<>