中文摘要：

在有效质量近似和绝热近似下,利用转移矩阵法研究了电子通过InAs/InP/InAs/InP/InAs柱形量子线共振隧穿二极管的输运问题,分析和讨论了电子居留时间以及电子的逃逸过程.详细研究了外加电场、结构尺寸效应对居留时间和电子逃逸的影响.居留时间随电子纵向能量的演化呈现出共振现象;同时,结构的非对称性对电子居留时间有很大的影响,随着结构非对称性的增加,居留时间表现出不同的变化.利用有限差分方法研究了非对称耦合量子盘中电子的相干隧穿逃逸过程.

英文摘要：

Within the framework of the effective mass and adiabatic approximation, the electron transport through an In As/InP cylindrical quantum wire is studied by using the transfer matrix method. The coherent and escape tunneling processes are analyzed in detail. Influence of external voltage and structure size on the dwell time and escape time are discussed theoretically. A resonant phenomenon of the dwell time for different electron longitudinal energies is observed. A peak value of dwell time appearing at some positions of the bound state increases as the energy level decreases. When a bias is applied on this system along the growth direction, all the peaks of the dwell time shift towards the lower energy and become higher with increasing bias. Furthermore, it can be seen that the asymmetry of structure affects the dwell time obviously. Different results are obtained with the increase of asymmetry of the structure, which can be attributed to a competition between the transmission probabilities through the whole structure and that through a single barrier.Besides, the coherent and escape tunneling processes are also investigated by using a finite-difference method between two asymmetrically coupled quantum disks. It is found that the coherent electron remains oscillating in the two coupled disks. When the right barrier thickness of the nanowire is decreased, a roughly exponential decay of the oscillation charge trapped in both quantum disks is observed. The oscillating period is not affected by the right barrier thickness.However, a great influence of the middle barrier on the oscillation period can be found easily.