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Quantum optical microcombs

Abstract

A key challenge for quantum science and technology is to realize large-scale, precisely controllable, practical systems for non-classical secured communications, metrology and, ultimately, meaningful quantum simulation and computation. Optical frequency combs represent a powerful approach towards this goal, as they provide a very high number of temporal and frequency modes that can result in large-scale quantum systems. The generation and control of quantum optical frequency combs will enable a unique, practical and scalable framework for quantum signal and information processing. Here, we review recent progress on the realization of energy–time entangled optical frequency combs and discuss how photonic integration and the use of fibre-optic telecommunications components can enable quantum state control with new functionalities, yielding unprecedented capability.

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Fig. 1: Biphoton emission of two correlated photons (called signal and idler) through SPDC or SFWM from filtered nonlinear waveguides or nonlinear resonators.
Fig. 2: Correlation signature of time–energy entangled photons.
Fig. 3: Biphoton quantum frequency comb characteristics.
Fig. 4: Complex quantum states from microring quantum combs.
Fig. 5: Concept of QFP with three elements.
Fig. 6: Experimental examples of frequency-bin gates.

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Acknowledgements

We thank J. Azaña, L. Caspani, P. Roztocki, S. Sciara, Y. Zhang, B. E. Little, S. T. Chu, N. Lingaraju and P. Lougovski for discussions. We acknowledge funding from: Canada Research Chairs (MESI PSR-SIIR); Natural Sciences and Engineering Research Council of Canada (NSERC); H2020 Marie Skłodowska-Curie Actions (MSCA) (656607); ITMO Fellowship and Professorship Program (08-08); 1000 Talents Sichuan Program; Australian Research Council (ARC) (DP150104327); John Templeton Foundation (JTF) number 60478; US Department of Energy, Office of Science, Office of Advanced Scientific Computing Research Quantum Algorithm Teams; Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the US Department of Energy; National Science Foundation under award number 1839191-ECCS.

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Kues, M., Reimer, C., Lukens, J.M. et al. Quantum optical microcombs. Nature Photon 13, 170–179 (2019). https://doi.org/10.1038/s41566-019-0363-0

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