【摘要】 在自由电子近似下,利用散射矩阵方法研究了两端光滑连着电子库、宽度呈宽-窄-宽和窄-宽-窄非绝热变化量子线(量子波导)的电子输运性质.用Landauer-Büttiker公式解析地计算出了两种情况下系统电子透射率作为入射电子能量和系统几何参数的函数表达式,从而分析得出了由于量子干涉产生透射极大与极小值时入射能量与几何参数所满足的条件关系并得到了数值验证.这种简单体系的精确解除有重要的基础性意义外,能为研究考虑各种相互作用、外场特别是含时外场作用下的介观电子输运问题提供一个“零级近似”的参考.更多还原

【Abstract】 Studied the electron transport properties for a quantum wire(quantum waveguide) with variation width of wide-narrow-wide and narrow-wide-narrow connected two electrodes in the framework of free-electron by means of scattering materix.Using Landauer-Buttiker formulism the analytical expressions for the electronic transmission probability as a function of incident electron energy and geometry parameters are obtained,with which the conditions for interference maximum and minimum of electron wave are indicated analytically and verified numerically.This exact solution for simple system is important for the understand basic physics.Moreover,it can provide a zeroth order aproximate solution for the system containing various interactions.更多还原