Quantum dot micro-cavity solid-state quantum light sources

本项目主要研究用于量子通信和信息处理的固态微腔量子点系统的实现和应用。它的目标是开发所需的工具，实现前所未有的高效光量子状态来源。设想的平台由嵌入在工程微腔结构中的量子点组成。这种方法将允许量子光源的质量不容易在现有的系统中实现。特别是我们的目标是设计、制造和表征两种类型的光子器件的共振激发。第一种装置将由单个量子点组成，它确定性地嵌入到专门设计的柱状微腔中，以增强线偏振单光子的发射。这种增强将通过实施非对称柱状微腔来实现。微腔的设计将以这种方式进行调整，以最大限度地提高发射光子的相干性和收集效率。我们的第二个设备将解决宽带光子结构中的Purcell增强问题。这样的实现对于有效地收集由单个量子点发射的光子对是非常必要的。此外，适度的Purcell增强允许收集具有非常高的波包相干性的光子。这将通过实现带有锥形柱子的微腔来实现。所实现的器件将通过最先进的共振激光光谱学进行测试，包括双光子激发技术，以确定地在发射器中产生双激子状态。这种方法将允许非常有效地产生具有非常高纠缠度的时间绑定纠缠光子和时分复用多光子纠缠态等实验。我们的实验将最终测试微腔收集增强方法的能力，使量子光源适合于未来的片上或片外量子网络和光子量子仿真器。

This project focuses on the realization and application of a solid-state microcavity quantum dot system for quantum communication and information processing. It has as a target the development of tools needed achieve unprecedentedly efficient sources of quantum states of light. The envisioned platform consists of quantum dots embedded in an engineered microcavity structures. This approach will allow for quantum light source qualities not easily achievable in the existing systems.In particular we aim at design, fabrication, and characterization in resonant excitation, of two types of photonic devices. The first device will consist of a single quantum dot that is deterministically embedded in a pillar microcavity specifically designed to enhance emission of linearly polarized single photons. This enhancement will be achieved by implementation of an asymmetric pillar microcavity. The microcavity design will be adapted in such a way, to maximize the coherence of the emitted photons as well as collection efficiency. Our second device will address the problem of Purcell enhancement in broadband photonic structures. Such an implementation is strongly required for efficient collection of pairs of photons emitted by a single quantum dot. In addition, a moderate Purcell enhancement allows for collection of photons with very high coherence of the wavepacket. This will be achieved by implementation of microcavities with a tapered pillar.The implemented devices will be tested by state-of-the-art resonant laser spectroscopy including two-photon excitation techniques to deterministically create biexcitonic states in the emitter. This approach will allow for experiments such as very efficient generation of time-bin entangled photons with very high degree of entanglement and time multiplexed multi-photon entangled states. Our experiments will ultimately test the capability of the microcavity collection enhancement approach to make quantum light sources suitable for future on- or off- chip quantum networks and photonic quantum emulators.