Nonlinear and Quantum Optics of Nanostructures

我的团队正在从理论上和计算上研究半导体纳米结构中电子和光子的非线性和量子行为。半导体纳米结构是一种长度范围为1到5000亿分之一米的半导体。这些结构的小尺寸强烈地影响了系统中电子和光子的行为。电子的限制导致了量子力学效应，类似于在原子中引起能级量子化的效应。此外，光子在一种称为光子晶体的特殊纳米结构中的界面反射可以捕获光子，从而导致该结构中光子和电子之间的相互作用发生巨大变化。由于电子和光子约束的结合，纳米结构的光学和电学性质与组成材料有很大的不同。仔细设计和利用纳米结构中的约束诱导效应可以产生可用于各种应用和设备的系统。我的提案涉及这个大研究领域的以下两个子领域：***I)半导体纳米结构的线性和非线性太赫兹响应：我研究的这一部分的目标是开发半导体纳米结构对太赫兹（THz）辐射响应的准确和有效的模型，太赫兹（THz）辐射是一种频率介于可见光和微波之间的电磁辐射形式。作为本研究的一部分，我们将研究半导体超晶格作为太赫兹放大器的使用。我们还将模拟单层和双层石墨烯的非线性太赫兹响应，这是一种令人兴奋的新型二维碳材料，被预测为高度非线性。这种非线性可用于制造高频源或超快太赫兹开关。总之，我在这一领域的工作将有助于开发更高功率、更宽带宽的太赫兹源。***II)光子晶体耦合腔系统中的非线性和量子光学：本工作的目的是发展光子晶体板中耦合腔中光动力学的理论处理。这项工作的一部分将是利用一种称为自发四波混频的非线性过程来模拟这些系统中光学光子对的产生。这种系统有望作为集成的单光子源应用于量子信息系统。工作的第二部分是使用太赫兹光子晶体来增强太赫兹场与石墨烯的相互作用，从而能够更灵敏地测量非线性响应。***从事这项研究的研究生和本科生将学习光学和纳米科学的最新理论和计算方法，并将为从事光电子和纳米技术的职业做好准备

My group is working to theoretically and computationally investigate the nonlinear and quantum 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 to 500 billionths of a metre.  The small size of these structures strongly affects the behaviour of both electrons and photons in the system. The confinement of the electrons results in quantum mechanical effects similar to those that cause energy-level quantization in an atom. In addition, the reflections of the photons at interfaces in a particular type of nanostructure called a photonic crystal can trap the photons, resulting in large changes in the interactions between photons and electrons in the structure.  Due to the combination of electron and photon confinement, the optical and electrical properties of nanostructures are very different than those of the constituent materials.  The careful design and exploitation of confinement-induced effects in nanostructures can produce systems that can be used in a wide variety of applications and devices. My proposal tackles the following two subfields of this large research area: ***I) The linear and nonlinear terahertz response of semiconductor nanostructures:  The goal in this part of my research is to develop accurate and efficient models of the response of semiconductor nanostructures to terahertz (THz) radiation, which is a form of electromagnetic radiation with frequencies between the visible and microwave. As part of this research, we will examine the use of semiconductor superlattices as THz amplifiers. We will also model the nonlinear THz response of monolayer and bilayer graphene, which are exciting new two-dimensional carbon materials that are predicted to be highly nonlinear. This nonlinearity can be used to produce higher-frequency sources or ultrafast THz switches. Altogether, my work in this area will aid in the development of higher power, wider bandwidth THz sources.***II) Nonlinear and quantum optics in photonic crystal coupled-cavity systems:   The aim of this work is to develop theoretical treatments of the dynamics of light in coupled cavities in photonic crystal slabs.  Part of this work will be to model the generation of optical photon pairs in these systems using a nonlinear process know as spontaneous four wave mixing. Such systems show promise as integrated single-photons sources for use in quantum information systems. The second part of the work is to use THz photonic crystals to enhance the interaction of terahertz fields with graphene to enable a more sensitive measurement of the nonlinear response.***The graduate and undergraduate students working on this research will learn the latest theoretical and computational methods in optics and nanoscience and will be well-positioned to pursue careers in optoelectronics and nanotechnology.**