Enhanced Quantum Dot Sources and Optical Atomic Memories for Telecommunication InterConnectivity

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.