Letter | Published:

Heralded entanglement between solid-state qubits separated by three metres

Nature volume 497, pages 8690 (02 May 2013) | Download Citation

Abstract

Quantum entanglement between spatially separated objects is one of the most intriguing phenomena in physics. The outcomes of independent measurements on entangled objects show correlations that cannot be explained by classical physics. As well as being of fundamental interest, entanglement is a unique resource for quantum information processing and communication. Entangled quantum bits (qubits) can be used to share private information or implement quantum logical gates1,2. Such capabilities are particularly useful when the entangled qubits are spatially separated3,4,5, providing the opportunity to create highly connected quantum networks6 or extend quantum cryptography to long distances7,8. Here we report entanglement of two electron spin qubits in diamond with a spatial separation of three metres. We establish this entanglement using a robust protocol based on creation of spin–photon entanglement at each location and a subsequent joint measurement of the photons. Detection of the photons heralds the projection of the spin qubits onto an entangled state. We verify the resulting non-local quantum correlations by performing single-shot readout9 on the qubits in different bases. The long-distance entanglement reported here can be combined with recently achieved initialization, readout and entanglement operations9,10,11,12,13 on local long-lived nuclear spin registers, paving the way for deterministic long-distance teleportation, quantum repeaters and extended quantum networks.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

References

  1. 1.

    & Quantum Computation and Quantum Information (Cambridge Univ. Press, 2000)

  2. 2.

    & One-way quantum computer. Phys. Rev. Lett. 86, 5188–5191 (2001)

  3. 3.

    et al. Entanglement of single-atom quantum bits at a distance. Nature 449, 68–71 (2007)

  4. 4.

    et al. An elementary quantum network of single atoms in optical cavities. Nature 484, 195–200 (2012)

  5. 5.

    et al. Heralded entanglement between widely separated atoms. Science 337, 72–75 (2012)

  6. 6.

    The quantum internet. Nature 453, 1023–1030 (2008)

  7. 7.

    , , & Long-distance quantum communication with atomic ensembles and linear optics. Nature 414, 413–418 (2001)

  8. 8.

    , , & Fault-tolerant quantum communication based on solid-state photon emitters. Phys. Rev. Lett. 96, 070504 (2006)

  9. 9.

    et al. High-fidelity projective read-out of a solid-state spin quantum register. Nature 477, 574–578 (2011)

  10. 10.

    et al. Single-shot readout of a single nuclear spin. Science 329, 542–544 (2010)

  11. 11.

    et al. Multipartite entanglement among single spins in diamond. Science 320, 1326–1329 (2008)

  12. 12.

    et al. Room-temperature quantum bit memory exceeding one second. Science 336, 1283–1286 (2012)

  13. 13.

    et al. Demonstration of entanglement-by-measurement of solid-state qubits. Nature Phys. 9, 29–33 (2013)

  14. 14.

    et al. Quantum computers. Nature 464, 45–53 (2010)

  15. 15.

    et al. Quantum entanglement between an optical photon and a solid-state spin qubit. Nature 466, 730–734 (2010)

  16. 16.

    , , , & Observation of entanglement between a quantum dot spin and a single photon. Nature 491, 426–430 (2012)

  17. 17.

    et al. Quantum-dot spin–photon entanglement via frequency downconversion to telecom wavelength. Nature 491, 421–425 (2012)

  18. 18.

    et al. Two-photon quantum interference from separate nitrogen vacancy centers in diamond. Phys. Rev. Lett. 108, 043604 (2012)

  19. 19.

    et al. Quantum interference of single photons from remote nitrogen-vacancy centers in diamond. Phys. Rev. Lett. 108, 143601 (2012)

  20. 20.

    et al. Two-photon interference of the emission from electrically tunable remote quantum dots. Nature Photon. 4, 632–635 (2010)

  21. 21.

    et al. Interference of single photons from two separate semiconductor quantum dots. Phys. Rev. Lett. 104, 137401 (2010)

  22. 22.

    , , , & Gigahertz dynamics of a strongly driven single quantum spin. Science 326, 1520–1522 (2009)

  23. 23.

    , , , & Universal dynamical decoupling of a single solid-state spin from a spin bath. Science 330, 60–63 (2010)

  24. 24.

    et al. Decoherence-protected quantum gates for a hybrid solid-state spin register. Nature 484, 82–86 (2012)

  25. 25.

    et al. Room-temperature entanglement between single defect spins in diamond. Nature Phys. 9, 139–143 (2013)

  26. 26.

    & Efficient high-fidelity quantum computation using matter qubits and linear optics. Phys. Rev. A 71, 060310 (2005)

  27. 27.

    , , , & Electrical tuning of single nitrogen-vacancy center optical transitions enhanced by photoinduced fields. Phys. Rev. Lett. 107, 266403 (2011)

  28. 28.

    , , & Control and coherence of the optical transition of single nitrogen vacancy centers in diamond. Phys. Rev. Lett. 105, 177403 (2010)

  29. 29.

    , & Measurement of subpicosecond time intervals between two photons by interference. Phys. Rev. Lett. 59, 2044–2046 (1987)

  30. 30.

    et al. Observation of the dynamic Jahn-Teller effect in the excited states of nitrogen-vacancy centers in diamond. Phys. Rev. Lett. 103, 256404 (2009)

  31. 31.

    , & Diamond photonics. Nature Photon. 5, 397–405 (2011)

Download references

Acknowledgements

We thank F. Jelezko, P. Kok, M. Lukin, J. Morton, E. Togan and L. Vandersypen for discussions and comments, and R. N. Schouten and M. J. Tiggelman for technical assistance. We acknowledge support from the Dutch Organization for Fundamental Research on Matter (FOM), the Netherlands Organization for Scientific Research (NWO), the DARPA QuASAR programme, the EU SOLID, DIAMANT and S3NANO programmes and the European Research Council through a Starting Grant.

Author information

Affiliations

  1. Kavli Institute of Nanoscience Delft, Delft University of Technology, PO Box 5046, 2600 GA Delft, The Netherlands

    • H. Bernien
    • , B. Hensen
    • , W. Pfaff
    • , G. Koolstra
    • , M. S. Blok
    • , L. Robledo
    • , T. H. Taminiau
    •  & R. Hanson
  2. Element Six Ltd, Kings Ride Park, Ascot, Berkshire SL5 8BP, UK

    • M. Markham
    •  & D. J. Twitchen
  3. McGill University Department of Physics, 3600 Rue University, Montreal, Quebec H3A 2T8, Canada

    • L. Childress

Authors

  1. Search for H. Bernien in:

  2. Search for B. Hensen in:

  3. Search for W. Pfaff in:

  4. Search for G. Koolstra in:

  5. Search for M. S. Blok in:

  6. Search for L. Robledo in:

  7. Search for T. H. Taminiau in:

  8. Search for M. Markham in:

  9. Search for D. J. Twitchen in:

  10. Search for L. Childress in:

  11. Search for R. Hanson in:

Contributions

H.B., B.H., L.R, L.C. and R.H. designed the experiment. H.B., B.H., W.P., G.K. and M.S.B. performed the experiments. H.B., B.H., W.P., G.K., M.S.B., T.H.T. and R.H. analysed the results. H.B., M.M. and D.J.T. fabricated the devices. H.B., B.H., W.P., M.S.B., L.C. and R.H. wrote the manuscript. All authors discussed the results and commented on the manuscript.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to R. Hanson.

Supplementary information

PDF files

  1. 1.

    Supplementary Information

    This file contains Supplementary Text and Data, Supplementary Figures 1-9 and additional references.

About this article

Publication history

Received

Accepted

Published

DOI

https://doi.org/10.1038/nature12016

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.