Electronic Transport Properties Of Semiconductor Quantum Wire Under Electromagnetic Field Irradiation

The properties of electronic transport of quantum wires (nanowires) have been intensively concerned. These properties are not only significal basic physical problems but also are of important potential application in the future as the theoretical basis of tomorrow's nanocircuit and nariodevice. Using Landauer-Biittiker transport theory and the scattering matrix method in this thesis, we study the electronic transport properties of quantum wires with different geometrical shapes and the electronic transport properties of a straight quantum wire partly irradiated by transversely polarized THz electromagnetic wave and we deduce the conductance formula of a straight quantum wire partly irradiated by longitudinally polarized electromagnetic wave, respectively. All these studies are within the framework of free electron.The thesis consists of five chapters. In chapter one we briefly introduce the theory of electronic transport in mesoscopic physics and scattering matrix method.In chapter two we study the electonic transport properties of quantum wire effected by the wire's geometrical parameters.Two different shapes of wide-narraw-wide and narraw-wide-narraw are corcerned,respcctively.We find the electron transport properties of them are completely different ,the conclusions are: 1. we predict interference phenomenon and coherent transport in wide-narraw-wide quantum wire. 2. we predict bound-state which leads to the zero transimission probability in narraw-wide-narraw quantum wire.Chapter three studies the electronic transport properties of a straight quantum wire partly irradiated by an transversely polarized THz electromagnetic wave. Using time-dependent mode matched scattering matrix method and the theory of the interaction between a two-level atom and electromagnetic field to solve time-dependent schr dinger equation, we predict the effect that the longitudinal transport of electron is partly blocked by the lateral emitting electromagnetic wave. We conclude that when the frequency of the external field is resonant with the separation of lateral levels of the quantum wire, 1.the occupation probabilities of the two lateral levels yield spacial Rabi oscillation in irradiated area; 2. the area irradiated by the electromagnetic field can give scattering effect and the transmission curve with emitting energy of electron shows an abnormal step;In chapter four we deduce the conductance formula of a straight quantum wire partly irradiated by a longitudinally polarized electromagntic wave.Using the method that widely used in dealing with quantum trap irradiated by laser to solve the time-dependent schrodinger equation and time-dependent mode matched scattering matrix method too.In chapter five a summary of the work and a outlook of this aspect are given.