Microscopic theory of light emission from semiconductor quantum dots in microcavities

微腔半导体量子点发光的微观理论

• 批准号: 5380223
• 负责人: Professor Dr. Frank Jahnke
• 金额: --
• 依托单位: Institut für Theoretische Physik (ITP)
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2009-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5380223?language=en
• 关键词: Microscopic; theory; light; emission; semiconductor

Semiconductor microcavities have been successfully used in the past decade to study fundamental light-matter effects. Previous investigations mainly used quantum wells as active material and Bragg mirrors for a one-dimensional cavity. Our goal is to extend these investigations in two directions: i) In quantumwell nanostructures, the intrinsic interaction processes of carriers (especially the Coulomb interaction) dominate also the light-matter interaction. The use of semiconductor quantum dots for the active material allows to modify these interaction processes and the discrete nature of the electronic states is the key for new light-matter interaction effects involving, e.g., single or few photons. ii) A three-dimensional photonic confinement will be necessary to realize the strong-coupling regime with quantum dots. Furthermore, the three-dimensional photon confinement strongly increases the spontaneous emission coupling which enhances quantum effects in the light emission. A microscopic theory will be used to study the emission properties of quantum dots in semiconductor microcavities. Starting from the electronic states of the quantum dots, electronic relaxation processes and their influence on the excitonic properties (in the low-excitation regime) and on the optical gain (under high-excitation conditions) will be studied. Calculations of the three-dimensional mode structure of semiconductor microcavities will be used to determine the altered spontaneous emission properties in the weak-coupling regime. Furthermore, within a quantum mechanical theory of the light-matter interaction, statistical properties of the light-emission will be investigated. For large spontaneous-emission coupling intensity-intensity correlations in the coupled cavity--quantum-dot system will be studied. In the weak excitation-limit quantumoptical effects like the creation of entangled photons for the biexciton-exciton transition will be analyzed in direct collaboration with the experimental investigations of our research group.

在过去的十年中，半导体微腔已经成功地用于研究基本的光物质效应。以往的研究主要是利用量子阱作为活性材料和一维腔体的布拉格反射镜。我们的目标是在两个方向上扩展这些研究：i)在量子阱纳米结构中，载流子的内在相互作用过程（特别是库仑相互作用）也主导着光-物质相互作用。使用半导体量子点作为活性材料可以改变这些相互作用过程，电子状态的离散性质是涉及单光子或少数光子的新型光物质相互作用效应的关键。ii)三维光子约束是实现量子点强耦合的必要条件。此外，三维光子约束增强了自发发射耦合，增强了光发射中的量子效应。用微观理论研究半导体微腔中量子点的发射特性。从量子点的电子态出发，研究电子弛豫过程及其对激子性质（低激发状态下）和光增益（高激发条件下）的影响。计算半导体微腔的三维模式结构将用于确定在弱耦合状态下改变的自发发射特性。此外，在光-物质相互作用的量子力学理论中，将研究光发射的统计特性。对于大自发发射耦合强度，将研究耦合腔-量子点系统的强度相关性。在弱激发极限下，双激子-激子跃迁产生的纠缠光子等量子光学效应将与本研究组的实验研究直接合作进行分析。