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Generation and sampling of quantum states of light in a silicon chip


Implementing large instances of quantum algorithms1,2,3,4,5 requires the processing of many quantum information carriers in a hardware platform that supports the integration of different components6. Although established semiconductor fabrication processes can integrate many photonic components7, the generation and algorithmic processing of many photons has been a bottleneck in integrated photonics. Here, we report the on-chip generation and algorithmic processing of quantum states of light with up to eight photons. Switching between different optical pumping regimes, we implement the scattershot8,9, Gaussian10 and standard boson sampling3,11,12,13,14 protocols in the same silicon chip, which integrates linear and nonlinear photonic circuitry. We use these results to benchmark a quantum algorithm for calculating molecular vibronic spectra4. Our techniques can be readily scaled for the on-chip implementation of specialized quantum algorithms with tens of photons, pointing the way to efficiency advantages over conventional computers15.

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Data availability

The data that support the plots within this paper and other findings of this study are available at https://doi.org/10.6084/m9.figshare.7492991.


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The authors thank N. Maraviglia, R. Chadwick, C. Sparrow, L. Banchi, G. Sinclair and D. Bacco for useful discussions and W.A. Murray, M. Loutit, E. Johnston, H. Fedder, M. Schlagmüller, M. Borghi and J. Lennon for technical assistance. The authors acknowledge support from the Engineering and Physical Sciences Research Council (EPSRC), the European Research Council (ERC) and European Commission (EC) funded grants PICQUE, BBOI, QuChip, QuPIC, QITBOX, Quantera-eranet Square, VILLUM FONDEN, QUANPIC (ref. 00025298) and the Center of Excellence, Denmark SPOC (ref. DNRF123). J.W. acknowledges support from the Beijing Academy of Quantum Information Sciences (Y18G21) and from The Key R&D Program of Guangdong province (2018B030329001). A.L. acknowledges fellowship support from EPSRC (EP/N003470/1).

Author information

S.P., Y.D., R.S., J.W., M.G.T. and A.L. designed the experiment. Y.D. fabricated the silicon photonics device. S.P., R.S. and C.V. performed the experiment. S.P. and L.C. analysed the data. S.P., Y.D., R.S., L.C. and A.L. wrote the manuscript with feedback from all authors. K.R., L.K.O., M.G.T. and A.L. managed the project.

Correspondence to Yunhong Ding or Jianwei Wang or Mark G. Thompson or Anthony Laing.

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The authors declare no competing interests.

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Peer review information: Nature Physics thanks Sonja Barkhofen, Robert Keil and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Fig. 1: Silicon photonic chip and experimental configuration.
Fig. 2: Results for SBS.
Fig. 3: Experimental results for GBS.
Fig. 4: Reconstructed FC profile.