Quantum Communications using integrated photonic devices

量子信息处理为传统技术提供了一个强大的替代方案。量子通信提供了从根本上安全的加密协议，并使量子态的分布式操作能够用于计算，传感和模拟应用。集成光子器件是实现复杂线性光电路的强大技术平台。本博士项目旨在进一步发展和理解基于集成光子器件的量子通信技术。有两个基本领域将成为目标：首先是利用d维光子量子态进行量子通信应用和纠缠分布，其次是在芯片上使用本地开发的量子节点为多个用户实现与测量设备无关的QKD协议。此外，该项目将探索使用多芯光纤进行信号稳定，以及使用基于单光子态空间复用的量子灯方法进行自由空间多维量子态传输。博士项目将嵌入到现有的欧盟项目SQUARE中，该项目用于开发基于高维量子态分布的量子网络，以及量子通信枢纽，这是一个国家多机构倡议，用于开发量子通信系统。这些正在进行的研究项目由布里斯托大学的QETLabs实验室主持，并得到了多位博士后研究人员和学生的支持。实验设施包括3个实验自动化和半自动光子芯片装置，以及共享的光子设备，如激光器、单光子探测器、功率表和光纤网络。目前已有数十种光子芯片用于量子态的产生和分析，未来几年将通过现有的拨款获得新的器件。

Quantum information processing offers a powerful alternative to conventional technologies. Quantum communications offer fundamentally secure encryption protocols and enable the distributed operation of quantum states for applications in computing, sensing and simulations. Integrated photonic devices are a robust technological platform for the realisation of complex linear optic circuits.This PhD project aims to further the development and understanding of quantum communication technologies based on integrated photonic devices. There are two fundamental areas that will be targeted: first the exploitation of d-dimensional photonic quantum states for quantum communication applications and entanglement distribution, and second the implementation of Measurement-Device-Independent QKD protocols on-chip using locally-developed quantum nodes for multiple users. Additionally, the project will explore the use of multi-core optical fibres for signal stabilisation, as well as free-space multi-dimensional quantum state transmission using a quantum lantern approach, based on space multiplexing of single photon states.The PhD project will be embedded in the existing EU project SQUARE for the development of quantum networks based on the distribution of high-dimensional quantum states, and the Quantum Communications HUB, a national multi-institutional initiative to develop quantum communications systems. These on-going research projects are hosted at Bristol in the QETLabs laboratories and are supported by multiple (4) postdoctoral researchers and students (4). The experimental facilities comprise 3 experimental automated and semi-automated photonic chip setups, as well as access to shared photonic equipment such as lasers, single photon detectors, power meters and fibre network. There are tens of copies of photonic chips used for quantum state generation and analysis, with new devices to be obtained through the existing grants in the coming years.