Enhanced Quantum Dot Sources and Optical Atomic Memories for Telecommunication InterConnectivity

一些光子量子通信和网络的实现需要开发关键元件，如确定的量子光源和量子存储器。目前，工作在电信波长的半导体量子点是一种非常有吸引力的系统，可以在合适的波长产生具有高亮度的单光子和纠缠光子。然而，目前在量子点中存储量子信息是困难的。另一方面，热原子蒸气构成了一个有吸引力的存储单光子的平台，尽管使用它们来产生确定的光子更具挑战性。在这里，我们计划实现一个混合量子系统，使用电信波长的量子点来产生纠缠光子对，以及一个热原子离共振级联吸收(ORCA)存储器来存储来自纠缠对的单光子。这将是在实验室环境之外实现量子网络的关键演示。在此基础上，我们的目标是对部署的光纤进行实验，测量存储在原子存储器中的光子与其他在光纤网络中远距离传播的光子之间的纠缠。在这里，我们将解决通过硅纤维远距离分布偏振纠缠时的几个应用研究挑战。此外，量子点纠缠光子源以及原子存储器将被高度优化，以共同发挥作用，形成有效的混合量子系统。

Several photonic quantum communication and network implementations require the development of key elements such as deterministic sources of quantum light as well as quantum memories. Currently, semiconductor quantum dots operating at telecom wavelength represent a very appealing system for the generation of single and entangled photons with high brightness at appropriate wavelengths. However, storing quantum information in quantum dots is currently difficult. On the other hand, warm atomic vapours constitute an attractive platform for storing single photons, though it is more challenging to use them for deterministic photon generation. Here we plan to realise a hybrid quantum system employing telecom-wavelength quantum dots for generating entangled photon pairs, and a warm atomic off resonant cascaded absorption (ORCA) memory to store single photons from the entangled pairs. This will represent a key demonstration for the realistic implementation of quantum networks outside of the lab environment. Building on this, we aim to perform experiments on deployed fibres, measuring entanglement between photons stored in the atomic memory and others propagating in the fibre network at long distance. Here we will tackle several applied research challenges when distributing polarisation entanglement over long distances via silica fibres. In addition, the quantum dot entangled-photon source as well as the atomic memory will be highly optimised to function together to form an effective hybrid quantum system.