电子在波导管中的输运研究

Research on the transmission of electron in electronwaveguide

我们用量子散射矩阵方法,从数值上研究了宽窄宽量子线的结构常数和结构中杂质对电子输运性质的影响.研究的具体模型为有限截面的电子波导管.数值结果告诉我们模型中电子的透射几率对模型的结构常数非常敏感;并被吸引势或排斥势抑制着,而且随着势的绝对值的增大,抑制作用增强;排斥势和吸引势的作用几乎相同.

We present a numerical study of the inuence of junction-geometries and disorder on quantum-me- chanical transmission by considering the presence of an impurity in a wide-narrow-wide （W-N-W） quantumwire junction. The device is modeled as an electron waveguide of finite cross section. Transmission and reflection probabilities as well asconductance are computed by using model expansions of the wave function together with waveguide-matching technique. The calculations show that the transmission of the two-dimensional electron gas through the W-N-W geometry is highly sensitive to geometries of junction and can be suppressed by the presence of a repulsive or attractive impurity potential. Furthermore, the depression effect becomes more visible if the absolute value of potential strength becomes bigger.