Designing time and frequency entanglement for generation of high-dimensional photon cluster states

The development of quantum technologies for quantum information science demands the realization and precise control of complex (multipartite and high dimensional) entangled systems on practical and scalable platforms. Quantum frequency combs (QFCs) generated via spontaneous four-wave mixing in integrated microring resonators represent a powerful tool towards this goal. They enable the generation of complex photon states within a single spatial mode as well as their manipulation using standard fiber-based telecommunication components. Here, we review recent progress in the development of QFCs, with a focus on our results that highlight their importance for the realization of complex quantum states. In particular, we outline our work on the use of integrated QFCs for the generation of high-dimensional multipartite optical cluster states and their unidirectional processing, being at the core of measurement-based quantum computation. These results confirm that engineering the time-frequency entanglement properties of QFC may provide a stable, practical, low-cost, and established platform for the development of near-future quantum devices for out-of-the-lab applications, ranging from practical quantum computing to more secure communications.