Nonlinear and quantum optics in two-dimensional materials and nanophotonic systems

操纵和利用光与纳米系统的相互作用是研究人员开发用于传统和量子信息系统的新一代芯片的中心目标。原则上，这种芯片将比目前的电子芯片更快，消耗更少的能量。我工作的一个中心目标是开发理论和计算模型，可供研究人员使用，以帮助设计“光子”芯片，在该芯片上可以产生，操纵和检测光。我所在小组的学生将接受光学、固态物理、量子信息理论和并行计算方面的高级理论技术培训。 石墨烯对太赫兹电场的响应：石墨烯是一种二维材料（TDM），由碳原子排列成六边形晶格。近年来，它吸引了相当多的科学和技术关注，这在很大程度上是由于其不寻常的电性能。它不仅具有非常低的电阻，而且电阻可以通过施加垂直于层的电压来调节，并且可以非线性地依赖于场强。我们正在开发太赫兹（1012 Hz）频率电场与石墨烯和其他TMD相互作用的理论和计算模型，目的是开发更好的石墨烯高频电导率模型。作为其中的一部分，我们将研究TMD表面上的杂质如何影响其线性和非线性电导率。我们还将设计波导结构来增强和利用石墨烯的非线性响应，从而利用谐波产生产生更高频率的太赫兹辐射源。总体而言，这项工作将有助于开发下一代纳米光子器件，包括光调制器，光学开关和高频源。 光的纠缠量子态的综合来源：目前全世界都在努力利用物质和光的量子性质来创造新一代量子技术。特别是，光的量子态显示出在量子密码学和量子计算中的应用前景。 虽然有桌面“散装”光学系统，可以用来产生许多这些状态的光，如果这些状态是在实际设备中使用，重要的是，我们开发纳米级（~10 - 9米）的芯片源。开发这种光源的关键困难之一是由于纳米光子平台中的表面粗糙度和光的不完美限制而产生的散射损失。我的研究的这一部分的主要重点是开发和应用的理论模型的产生和演化的纠缠量子态的光在集成纳米光子系统。这些模型将在帮助光量子计算系统的研究人员和开发人员最大限度地减少损耗对其性能的不利影响方面发挥重要作用。

Manipulating and exploiting the interaction of light with nanoscopic systems is a central objective of researchers developing a new generation of chips for use in traditional and quantum information systems. In principle, such chips will be faster and use less energy than current electronic chips. A central aim of my work is to develop theoretical and computational models that can be used by researchers to aid in the design of "photonic" chips on which light can be generated, manipulated and detected. Students in my group will be trained in advanced theoretical techniques in optics, solid state physics, quantum information theory and parallel computing. The response of graphene to terahertz electric fields: Graphene is a two-dimensional material (TDM) composed of carbon atoms arranged in a hexagonal lattice. It has attracted considerable scientific and technological attention in recent years in large part due to its unusual electrical properties. It not only has very low resistance, but the resistance can be tuned by applying a voltage perpendicular to the layer and can depend nonlinearly on the field strength. We are developing theoretical and computational models of the interaction of terahertz (1012 Hz) frequency electric fields with graphene and other TMDs, with the aim of developing better models of the high-frequency conductivity of graphene. As part of this, we will be investigating how impurities on the surface of TMDs affect their linear and nonlinear conductivity. We will also be designing waveguide structures to enhance and exploit the nonlinear response of graphene and thereby generate higher frequency sources of terahertz radiation using harmonic generation.Taken as a whole, this work will aid in the development of the next generation of nanophotonic devices, including light modulators, optical switches, and high-frequency sources. Integrated sources of entangled quantum states of light: There is currently a worldwide effort to exploit the quantum nature of matter and light to create a new generation of quantum technologies. In particular, quantum states of light show promise for use in quantum cryptography and quantum computing. Although there are tabletop "bulk" optical systems that can be used to generate many of these states of light, if these states are to be used in practical devices, it is important that we develop nanoscale (~10-9 m) on-chip sources. One of the key difficulties in developing such sources is the scattering losses that arise due to surface roughness and imperfect confinement of light in nanophotonic platforms. The primary focus of this part of my research is to develop and apply theoretical models of the generation and evolution of entangled quantum states of light in integrated nanophotonic systems. These models will play an important role in helping researchers and developers of optical quantum computing systems minimize the detrimental effects of loss on their performance.