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Quantum circuits with many photons on a programmable nanophotonic chip


Growing interest in quantum computing for practical applications has led to a surge in the availability of programmable machines for executing quantum algorithms1,2. Present-day photonic quantum computers3,4,5,6,7 have been limited either to non-deterministic operation, low photon numbers and rates, or fixed random gate sequences. Here we introduce a full-stack hardware−software system for executing many-photon quantum circuit operations using integrated nanophotonics: a programmable chip, operating at room temperature and interfaced with a fully automated control system. The system enables remote users to execute quantum algorithms that require up to eight modes of strongly squeezed vacuum initialized as two-mode squeezed states in single temporal modes, a fully general and programmable four-mode interferometer, and photon number-resolving readout on all outputs. Detection of multi-photon events with photon numbers and rates exceeding any previous programmable quantum optical demonstration is made possible by strong squeezing and high sampling rates. We verify the non-classicality of the device output, and use the platform to carry out proof-of-principle demonstrations of three quantum algorithms: Gaussian boson sampling, molecular vibronic spectra and graph similarity8. These demonstrations validate the platform as a launchpad for scaling photonic technologies for quantum information processing.

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Fig. 1: Overview of apparatus.
Fig. 2: Component statistics.
Fig. 3: Total photon-number distribution.
Fig. 4: GBS experiment.
Fig. 5: Vibronic spectra experiment.
Fig. 6: Graph similarity experiment.

Data availability

All data underlying the findings of this work are available upon request from the authors.

Code availability

Codes used for data analysis in this work are available upon request from the authors. The Supplementary Information contains example Strawberry Fields code, parameters of the theoretical model, and interferometer unitaries used in the demonstrations.


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Authors and Affiliations



B.M., D.H.M., A.G., J.L., M.M., K.T., Z.V. and Y.Z. designed and tested the chip, and developed its components. D.H.M. also led the development of the control hardware system, designing and building the machine alongside A.R. and V.D.V. M.J.C., T.G., A.E.L. and S.W.N. developed the photon detection system. L.N., L.G.H. and J.H. developed the control and data acquisition software. V.B., A.F., T.I., J.I., R.J., N.K., N.Q., J.S., A.S., P.T. and Z.Z. designed and deployed the platform for remote programming of the device. J.M.A., K.B., T.B., R.I., S.J., K.K.S., M.S. and D.S. designed, and implemented the demonstrations. I.D., S.P.K., H.Y.Q. and N.Q. designed and implemented the non-classicality test. Z.V. and J.M.A. led the project and wrote the manuscript with input from all authors.

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Correspondence to J. M. Arrazola or Z. Vernon.

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Supplementary information

Supplementary Information

This file contains Strawberry Fields coding, Supplementary Tables and Graphs.

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Arrazola, J.M., Bergholm, V., Brádler, K. et al. Quantum circuits with many photons on a programmable nanophotonic chip. Nature 591, 54–60 (2021).

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