Integrated Sources of Entangled and Indistinguishable Photons

量子光学和量子信息处理研究的变革性质已经改变了我们对自然及其与信息关系的思考方式。此外，用于安全通信的设备已经基于量子物理定律商业化。该领域的许多最引人注目的发展都与光的量子态有关。该项目将在微型化和集成方面将这些态的产生提升到一个新的水平，并旨在深入了解潜在的物理过程。在III-V族半导体系统中，我们将开发和研究非线性光学元件，单量子发射器和其他波导光学元件的量子光学平台。我们将利用这样一个事实：共振激发的量子点可以发射非常干净的单光子，随后的光子彼此难以区分，这对于多光子协议的任何使用都至关重要，例如在量子中继器中。此外，我们将利用布拉格反射波导，以促进光的有效非线性转换。期望的过程是自发的参数下转换，其将较短波长的泵浦光子转换为电信波长带中的纠缠光子对。在芯片上的方法，我们将研究和优化单光子和纠缠光子对的产生，通过共振耦合的电泵浦回音壁模式微激光器的输出到嵌入在相邻的微柱腔和布拉格反射波导的单量子点。虽然所有这些结构和组成部分以前都已实现，但没有一个达到我们目标的整合水平。除了技术上的挑战，还有许多令人兴奋的物理问题，例如深入理解纠缠光子对产生的非线性过程，我们的项目将解决这些问题。我们的工作将为量子光学平台奠定基础，这可能会彻底改变我们进行量子光学实验的方式，从长远来看可能成为一种新的量子技术。

The transformative nature of quantum optics and quantum information processing research has already changed the way we think about nature and its relation to information. Moreover, devices for secure communications have been commercialized based on the laws of quantum physics. Many of the most spectacular developments in the field have to do with quantum states of light.This project will take the production of these states to the next level in terms of miniaturization and integration and aims at an in-depth understanding of the underlying physical processes. In a III-V semiconductor system we will develop and study a quantum optics platform of nonlinear optical elements, single quantum emitters and other waveguide optical elements. We will take advantage of the fact that resonantly excited quantum dots can emit very clean single photons where subsequent photons are indistinguishable from each other, which is crucial for any use in multi-photon protocols, for example in quantum repeaters. Moreover, we will utilize Bragg-reflection waveguides to facilitate efficient nonlinear conversion of light. The desired process is spontaneous parametric down-conversion, which converts a shorter wavelength pump photon to an entangled pair of photons in the telecommunications wavelength band. Within an on-chip approach we will study and optimize the generation of single and entangled photon pairs by resonantly coupling the output of electrically pumped whispering gallery mode micro-lasers to single quantum dots embedded in adjacent micropillar cavities and Bragg-reflection waveguides. While all of these structures and building blocks have been realized before, no one has achieved the level of integration that we are targeting. Besides technological challenges, there exist a number of exciting physical questions such as an in-depth understanding of the non-linear processes involved in the generation of entangled photon pairs which will be tackled by our project.Our work will set the ground for a quantum optics platform that could revolutionize the way we conduct quantum optics experiments and may in the long run become a new quantum technology.