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Hybrid discrete- and continuous-variable quantum information

Abstract

Research in quantum information processing has followed two different directions: the use of discrete variables (qubits) and that of high-dimensional, continuous-variable Gaussian states (coherent and squeezed states). Recently, these two approaches have been converging in potentially more powerful hybrid protocols.

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Figure 1: Examples of non-Gaussian state generation in various systems.
Figure 2: Measurement-based quantum computation using two-dimensional lattices corresponding to offline-prepared, multi-mode cluster states.

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Acknowledgements

The authors gratefully acknowledge support from the Danish Council for Independent Research (Sapere Aude programmes under FTP and FNU), the Lundbeck Foundation, the Villum Foundation Young Investigator Programme, the Federal Ministry for Education and Research in Germany (Q.com), ERA-NET CHISTERA (Hipercom), the Ministry of Education, Culture, Sports, Science and Technology of Japan (PDIS - Project for Developing Innovation Systems, GIA - Grant-in-Aid for Scientific Research, and APSA - Advanced Photon Science Alliance), Universities Denmark, and Japan Society for the Promotion of Science.

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Andersen, U., Neergaard-Nielsen, J., van Loock, P. et al. Hybrid discrete- and continuous-variable quantum information. Nature Phys 11, 713–719 (2015). https://doi.org/10.1038/nphys3410

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