Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Generating, manipulating and measuring entanglement and mixture with a reconfigurable photonic circuit

Nature Photonics volume 6, pages 45–49 (2012)Cite this article

Subjects

Abstract

Entanglement is the quintessential quantum-mechanical phenomenon understood to lie at the heart of future quantum technologies and the subject of fundamental scientific investigations. Mixture, resulting from noise, is often an unwanted result of interaction with an environment, but is also of fundamental interest, and is proposed to play a role in some biological processes. Here, we report an integrated waveguide device that can generate and completely characterize pure two-photon states with any amount of entanglement and arbitrary single-photon states with any amount of mixture. The device consists of a reconfigurable integrated quantum photonic circuit with eight voltage-controlled phase shifters. We demonstrate that, for thousands of randomly chosen configurations, the device performs with high fidelity. We generate maximally and non-maximally entangled states, violate a Bell-type inequality with a continuum of partially entangled states, and demonstrate the generation of arbitrary one-qubit mixed states.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Learn more

Prices may be subject to local taxes which are calculated during checkout

Figure 1: A two-photon reconfigurable quantum circuit for generating, manipulating and detecting entanglement and mixture.
Figure 2: Classical and quantum interference fringes.
Figure 3: Statistical fidelity of photon coincidence count rates.
Figure 4: Bell states generated and characterized on-chip.
Figure 5: CHSH manifold.
Figure 6: Histogram showing the statistical distribution of quantum-state fidelity between 119 randomly chosen single-qubit target states and the corresponding mixed states generated and characterized on-chip.

References

  1. Nielsen, M. A. & Chuang, I. L. Quantum Computation and Quantum Information (Cambridge Univ. Press, 2000).

    MATH  Google Scholar 

  2. Deutsch, D. Quantum theory, the Church–Turing principle and the universal quantum computer. Proc. R. Soc. Lond. A 400, 97–117 (1985).

    Article  ADS  MathSciNet  Google Scholar 

  3. Feynman, R. P. Simulating physics with computers. Int. J. Theor. Phy. 21, 467–488 (1982).

    Article  MathSciNet  Google Scholar 

  4. Lloyd, S. Universal quantum simulators. Science 273, 1073–1078 (1996).

    Article  ADS  MathSciNet  Google Scholar 

  5. Gisin, N. & Thew, R. Quantum communication. Nature Photon. 1, 165–171 (2007).

    Article  ADS  Google Scholar 

  6. Giovannetti, V., Lloyd, S. & Maccone, L. Quantum-enhanced measurements: beating the standard quantum limit. Science 306, 1330–1336 (2004).

    Article  ADS  Google Scholar 

  7. Dowling, J. P. Quantum optical metrology — the lowdown on high-N00N states. Contemp. Phys. 49, 125–143 (2008).

    Article  ADS  Google Scholar 

  8. O'Brien, J. L., Furusawa, A. & Vuckovic, J. Photonic quantum technologies. Nature Photon. 3, 687–695 (2009).

    Article  ADS  Google Scholar 

  9. Clark, A. S., Fulconis, J., Rarity, J. G., Wadsworth, W. J. & O'Brien, J. L. All-optical-fiber polarization-based quantum logic gate. Phys. Rev. A 79, 030303 (2009).

    Article  ADS  Google Scholar 

  10. Hall, M. A., Altepeter, J. B. & Kumar, P. Ultrafast switching of photonic entanglement. Phys. Rev. Lett. 106, 053901 (2011).

    Article  ADS  Google Scholar 

  11. Politi, A., Cryan, M. J., Rarity, J. G., Yu, S. & O'Brien, J. L. Silica-on-silicon waveguide quantum circuits. Science 320, 646–649 (2008).

    Article  ADS  Google Scholar 

  12. Matthews, J. C. F., Politi, A., Stefanov, A. & O'Brien, J. L. Manipulation of multiphoton entanglement in waveguide quantum circuits. Nature Photon. 3, 346–350 (2009).

    Article  ADS  Google Scholar 

  13. Smith, B. J., Kundys, D., Thomas-Peter, N., Smith, P. G. R. & Walmsley, I. A. Phase-controlled integrated photonic quantum circuits. Opt. Express 17, 13516–13525 (2009).

    Article  ADS  Google Scholar 

  14. Politi, A., Matthews, J. C. F. & O'Brien, J. L. Shor's quantum factoring algorithm on a photonic chip. Science 325, 1221 (2009).

    Article  ADS  MathSciNet  Google Scholar 

  15. Sansoni, L. et al. Polarization entangled state measurement on a chip. Phys. Rev. Lett. 105, 200503 (2010).

    Article  ADS  Google Scholar 

  16. Laing, A. et al. High-fidelity operation of quantum photonic circuits. Appl. Phys. Lett. 97, 211109 (2010).

    Article  ADS  Google Scholar 

  17. Peruzzo, A., Laing, A., Politi, A., Rudolph, T. & O'Brien, J. L. Multimode quantum interference of photons in multiport integrated devices. Nature Commun. 2, 224 (2011).

    Article  ADS  Google Scholar 

  18. Honjo, T., Inoue, K. & Takahashi, H. Differential-phase-shift quantum key distribution experiment with aplanar light-wave circuit Mach–Zehnder interferometer. Opt. Lett. 29, 2797–2799 (2004).

    Article  ADS  Google Scholar 

  19. Ralph, T. C., Langford, N. K., Bell, T. B. & White, A. G. Linear optical controlled-NOT gate in the coincidence basis. Phys. Rev. A 65, 062324 (2002).

    Article  ADS  Google Scholar 

  20. Hofmann, H. F. & Takeuchi, S. Quantum phase gate for photonic qubits using only beam splitters and postselection. Phys. Rev. A 66, 024308 (2002).

    Article  ADS  Google Scholar 

  21. Reck, M., Zeilinger, A., Bernstein, H. J. & Bertani, P. Experimental realization of any discrete unitary operator. Phys. Rev. Lett. 73, 58–61 (1994).

    Article  ADS  Google Scholar 

  22. Hong, C. K., Ou, Z. Y. & Mandel, L. Measurement of subpicosecond time intervals between two photons by interference. Phys. Rev. Lett. 59, 2044–2046 (1987).

    Article  ADS  Google Scholar 

  23. Burnham, D. C. & Weinberg, D. L. Observation of simultaneity in parametric production of optical photon pairs. Phys. Rev. Lett. 25, 84–87 (1970).

    Article  ADS  Google Scholar 

  24. Natarajan, C. M. et al. Operating quantum waveguide circuits with superconducting single-photon detectors. Appl. Phys. Lett. 96, 211101 (2010).

    Article  ADS  Google Scholar 

  25. James, D. F. V., Kwiat, P. G., Munro, W. J. & White, A. G. Measurement of qubits. Phys. Rev. A 64, 052312 (2001).

    Article  ADS  Google Scholar 

  26. Clauser, J. F., Horne, M. A., Shimony, A. & Holt, R. A. Proposed experiment to test local hidden-variable theories. Phys. Rev. Lett. 23, 880–884 (1969).

    Article  ADS  Google Scholar 

  27. Lanyon, B. P., Barbieri, M., Almeida, M. P. & White, A. G. Experimental quantum computing without entanglement. Phys. Rev. Lett. 101, 200501 (2008).

    Article  ADS  Google Scholar 

  28. Mohseni, M., Rebentrost, P., Lloyd, S. & Guzik, A. A. Environment-assisted quantum walks in photosynthetic energy transfer. J. Chem. Phys. 129, 174106 (2008).

    Article  ADS  Google Scholar 

  29. Plenio, M. B. & Huelga, S. F. Dephasing-assisted transport: quantum networks and biomolecules. New J. Phys. 10, 113019 (2008).

    Article  ADS  Google Scholar 

  30. Perets, H. B. et al. Realization of quantum walks with negligible decoherence in waveguide lattices. Phys. Rev. Lett. 100, 170506 (2008).

    Article  ADS  Google Scholar 

  31. Peruzzo, A. et al. Quantum walks of correlated photons. Science 329, 1500–1503 (2010).

    Article  ADS  Google Scholar 

  32. Peters, N. A., Barreiro, J. T., Goggin, M. E., Wei, T. C. & Kwiat, P. G. Remote state preparation: arbitrary remote control of photon polarization. Phys. Rev. Lett. 94, 150502 (2005).

    Article  ADS  Google Scholar 

  33. Zyczkowski, K. & Sommers, H-J. Induced measures in the space of mixed quantum states. J. Phys. A. 34, 7111–7125 (2001).

    Article  ADS  MathSciNet  Google Scholar 

  34. Rossi, A., Vallone, G., Chiuri, A., De Martini, F. & Mataloni, P. Multipath entanglement of two photons. Phys. Rev. Lett. 102, 153902 (2009).

    Article  ADS  Google Scholar 

  35. Ceccarelli, R., Vallone, G., De Martini, F., Mataloni, P. & Cabello, A. Experimental entanglement and nonlocality of a two-photon six-qubit cluster state. Phys. Rev. Lett. 103, 160401 (2009).

    Article  ADS  Google Scholar 

  36. Saleh, M. F., Di Giuseppe, G., Saleh, B. E. A. & Teich, M. C. Modal and polarization qubits in Ti:LiNbO3 photonic circuits for a universal quantum logic gate. Opt. Express 18, 20475–20490 (2010).

    Article  ADS  Google Scholar 

  37. Saleh, M. F., Di Giuseppe, G., Saleh, B. E. A. & Teich, M. C. Photonic circuits for generating modal, spectral, and polarization entanglement. IEEE Photon. J. 2, 736–752 (2010).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

The authors thank N. Brunner, J. G. Rarity and P. Ivanov for helpful contributions. This work was supported by the Engineering and Physical Sciences Research Council (EPSRC), the European Research Council (ERC), Intelligence Advanced Research Projects Activity (IARPA), the Leverhulme Trust, the Centre for Nanoscience and Quantum Information (NSQI), PHORBITECH, the Quantum Information Processing Interdisciplinary Research Collaboration (QIP IRC), and the Quantum Integrated Photonics (QUANTIP) project. J.L.O'B. acknowledges a Royal Society Wolfson Merit Award. M.L. acknowledges the Marie Curie International Incoming Fellowship.

Author information

Authors and Affiliations

  1. H. H. Wills Physics Laboratory & Department of Electrical and Electronic Engineering, Centre for Quantum Photonics, University of Bristol, Merchant Venturers Building, Woodland Road, Bristol, BS8 1UB, UK

    P. J. Shadbolt, M. R. Verde, A. Peruzzo, A. Politi, A. Laing, M. Lobino, J. C. F. Matthews, M. G. Thompson & J. L. O'Brien

Authors
  1. P. J. Shadbolt
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. M. R. Verde
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. A. Peruzzo
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. A. Politi
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. A. Laing
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. M. Lobino
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. J. C. F. Matthews
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. M. G. Thompson
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. J. L. O'Brien
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

All authors contributed extensively to the work presented in this paper.

Corresponding author

Correspondence to J. L. O'Brien.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 4062 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Shadbolt, P., Verde, M., Peruzzo, A. et al. Generating, manipulating and measuring entanglement and mixture with a reconfigurable photonic circuit. Nature Photon 6, 45–49 (2012). https://doi.org/10.1038/nphoton.2011.283

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphoton.2011.283

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing