Electron Transport Properties for Quantum Wire with Nonadiabatical Variation of Width

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.