Exciton and photon dynamics in nanostructures

提出的研究是在理论上和计算上研究半导体纳米结构中电子和光子在很短时间尺度上的行为。半导体纳米结构是一种长度范围从十亿分之一米到五千亿分之一米不等的半导体。电子在这种结构中的限制导致了类似于导致原子中能级量子化的量子力学效应。光子在被称为光子晶体的纳米结构界面上的反射可以捕获光子，导致光子-电子相互作用的巨大变化。由于这些约束效应，纳米结构的光学和电学性质与组成材料有很大的不同。我将主要关注半导体超晶格、量子阱、量子点和光子晶体。对于这些结构，我将建立1)超短激光脉冲（~0.0000000000001秒长）启动纳米结构激子的超快动力学和2)半导体光子晶体中光子和激子的动力学的理论和计算模型。激子是半导体中的粒子，由一个被激发的电子与电子被激发时留下的“空穴”结合而成；它们在半导体的光学响应中起着核心作用。所开发的模型将预测从纳米结构发射和吸收的光的特性。这项研究将扩大对纳米结构激子和光子行为的认识。它还将有助于改进光电器件的设计，如激光、光开关和光放大器，这些都是信息技术的核心。研究的部分目的是建模和设计一种新型可调谐固态太赫兹激光器，这种激光器发射的光位于电磁波谱的微波和红外部分之间。另一个课题是改进基于光子晶体板的垂直腔面发射激光器的设计。最后，我的部分工作将有助于开发全新的量子信息处理设备。

The proposed research is to theoretically and computationally investigate the behaviour of electrons and photons in semiconductor nanostructures on very short time scales. Semiconductor nanostructures are semiconductors that are structured on length scales ranging from one billionth to 500 billionths of a metre. The confinement of the electrons in such structures results in quantum mechanical effects similar to those that cause the energy-level quantization in an atom. The reflections of the photons at interfaces in nanostructures called photonic crystals can trap the photons, resulting in large changes in the photon-electron interactions. As a result of these confinement effects, the optical and electrical properties of nanostructures are very different from those of the constituent materials. I will primarily focus on semiconductor superlattices, quantum wells, quantum dots and photonic crystals. For these structures, I will develop theoretical and computational models of 1) The ultra-fast dynamics of nanostructure excitons set into motion by ultra-short laser pulses (~0.0000000000001 seconds long) and 2) The dynamics of photons and excitons in semiconductor photonic crystals. Excitons are particles in semiconductors that consist of an excited electron bound to the "hole" that is left behind when the electron is excited; they play a central role in the optical response of the semiconductors. The models developed will predict the properties of the light emitted from and absorbed by the nanostructures. This research will expand the knowledge of the behaviour of nanostructure excitons and photons. It will also help improve the design of optoelectronic devices such as lasers, optical switches, and optical amplifiers that are at the heart of information technology. Part of the research is aimed at modelling and designing a new type of tuneable solidstate Terahertz laser, which emits light that lies between the microwave and infrared portions of the electromagnetic spectrum. Another topic is to improve the design of vertical cavity surface emitting lasers based on photonic crystal slabs. Finally, part of my work will aid in the development of entirely new quantum information processing devices.