The Dynamical Study Of The Escape Of Photo-detached Electron From A Circular Or Annular Microcavity

Over the past twenty year, the study of the nano-device (1~100nm) has gradually becomea hot topic. Researches on the structure and transport process in the microcavity will have asignificant impact for the study of a new generation of computers. This paper investigates theescape of photo-detached electron from a nano-circular or annular microcavity on the basis ofthe semiclassical theory. Hydrogen is the simplest atom, so the hydrogen negative ion is thesimplest ion. SinceH ion is a single-electron system, the binding energy between theactive electron and the hydrogen atom is very low, thus the photodetachment of hydrogennegative ion becomes much easier. After a beam of laser is irradiated on theH ion, theactive electron will be photo-detached and the short-ranged potential between the activeelectron and the hydrogen atom can be neglected. We study the escape orbits of thephoto-detached electron which emitted from the left entrance and escape from the differentposition of a circular or annular microcavity. Then we construct the semiclassical wavefunction of the detached electron at the exit of the microcavity, and give the formula forcalculating the escape probability density. We discuss the variation of the escape probabilitydensity of photo-detached electron in a circular or annular microcavity with the length ofescaped orbit, in different polarized laser light and for different inner radius. Finally weperform the Fourier transformation (FT) of the semiclassical wave function, which gives thepath length spectrum.The main study of this thesis includes three aspects:1. We studied the escape of photo-detached electron from an up-opened and right-openednano-circularmicrocavity. The calculation results suggest that significant oscillatory structuresappear in the escape probability density, which is caused by the quantum interference effect atthe exit. Besides, our study suggests that the oscillatory structure in the escape probabilitydensity depends not only on the length of the electron’s orbits, but also on the laserpolarization sensitively. Such as. If we make the laser polarization unchanged, increase thelength of the escaped orbit, the oscillating amplitude and frequency of the escaped probabilitydensity becomes strengthened; make the length of the escaped orbit unchanged, with theincrease of the angle of the laser polarization, the oscillating amplitude in the escapedprobability density becomes increased firstly, and then decreased again. In order to show the correspondence between the escaped probability density at the exit of the circular microcavityand the detached electron’s escaped orbits clearly, we calculate the path length spectrum. Wefind that a series of sharp peaks in the path length spectrum appear and each peak correspondsto the length of one escaped orbit.2. Escape of photo-detached electron from an annular nano-microcavity. The calculationresults suggest that the oscillatory structure in the escape probability density depends not onlyon the length of the electron’s orbits and the laser polarization, but also related to the innerradius of the annular microcavity. We find when the inner radius is not very large, theoscillating structure of the escaped probability density becomes more complicated than in thecircular microcaviy and the oscillating amplitude become larger; However, the number of theescaped orbits is falling down again when the inner radius of the annular nano-microcavity islarge.Similarly, we perform the Fourier transform of the wave function from the momentumto the length of the escape orbits, which gives the length spectrum. A series of sharp peaksappear, each peak corresponds to the length of one escaped orbit.3. We investigate the escape of photo-detached electron from a circular or annularmicrocavity with the position of the exit is arbitrary. For the circular microcavity, we study thecase with the distance of the exit from the entrance is R/3and2R/3, we discuss thevariation of the escaped probability density of the photo-detached electron in a circularmirocavity with the length of the escaped orbits. For the annular microcavity, we study thecase with the distance of the exit from the entrance is R/4and3R/4, we calculate theescaped probability density of the photo-detached electron in an annular mirocavity withdifferent inner radius. The results show that, with the change of the exit position, theoscillating amplitude and frequency in the escaped probability density become difference.Our study provides an example where the quantum nature of the electron’s wave functioncan be observed in the macroscopic world. Furthermore, our study may guide the futureexperimental research on the escape and transport process of particles through semiconductormicro-junctions.This thesis is divided into five chapters. The first chapter is the introduction, whichintroduces the research significance, the domestic and overseas research status, and theinnovation points of this thesis. In chapter two, we using seimiclassical theory investigate the escape of photo-detached electron from a circular nano-microcavity.In chapter three, weresearch the escape of photo-detached electron from an annular nano-microcavity. In chapterfour, we discuss the escape of photo-detached electron from a circular or annular microcavitywhere the export position is arbitrary. Some conclusions and prospects are given in chapterfive.