Skip to main content

Thank you for visiting 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.

Quantum teleportation across a metropolitan fibre network


If a photon interacts with a member of an entangled photon pair via a Bell-state measurement (BSM), its state is teleported over principally arbitrary distances onto the pair's second member1. Since 1997, this puzzling prediction of quantum mechanics has been demonstrated many times2. However, with two exceptions3,4, only the photon that received the teleported state, if any, travelled far, while the photons partaking in the BSM were always measured close to where they were created. Here, using the Calgary fibre network, we report quantum teleportation from a telecom photon at 1,532 nm wavelength, interacting with another telecom photon after both have travelled several kilometres and over a combined beeline distance of 8.2 km, onto a photon at 795 nm wavelength. This improves the distance over which teleportation takes place to 6.2 km. Our demonstration establishes an important requirement for quantum repeater-based communications5 and constitutes a milestone towards a global quantum internet6.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Aerial view of Calgary.
Figure 2: Schematics of the experimental set-up.
Figure 3: Indistinguishability of photons at Charlie.
Figure 4: Density matrices of four states after teleportation.
Figure 5: Individual and average fidelities of four teleported states with expected (ideal) states, measured using quantum state tomography (QST) and the decoy-state method (DSM).


  1. Bennett, C. H. et al. Teleporting an unknown quantum state via dual classical and Einstein–Podolsky–Rosen channels. Phys. Rev. Lett. 70, 1895–1899 (1993).

    ADS  MathSciNet  Article  Google Scholar 

  2. Pirandola, S., Eisert, J., Weedbrook, C., Furusawa, A. & Braunstein, S. L. Advances in quantum teleportation. Nat. Photon. 9, 641–652 (2015).

    ADS  Article  Google Scholar 

  3. Landry, O., van Houwelingen, J. A. W., Beveratos, A., Zbinden, H. & Gisin, N. Quantum teleportation over the Swisscom telecommunication network. J. Opt. Soc. Am. B 24, 398–403 (2007).

    ADS  Article  Google Scholar 

  4. Hensen, B. et al. Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres. Nature 526, 682–686 (2015).

    ADS  Article  Google Scholar 

  5. Sangouard, N., Simon, C., De Riedmatten, H. & Gisin, N. Quantum repeaters based on atomic ensembles and linear optics. Rev. Mod. Phys. 83, 33–80 (2011).

    ADS  Article  Google Scholar 

  6. Kimble, H. J. The quantum internet. Nature 453, 1023–1030 (2008).

    ADS  Article  Google Scholar 

  7. Yin, J. et al. Quantum teleportation and entanglement distribution over 100-kilometre free-space channels. Nature 488, 185–188 (2012).

    ADS  Article  Google Scholar 

  8. Ma, X.-S. et al. Quantum teleportation over 143 kilometres using active feed-forward. Nature 489, 269–273 (2012).

    ADS  Article  Google Scholar 

  9. Lvovsky, A. I., Sanders, B. C. & Tittel, W. Optical quantum memory. Nat. Photon. 3, 706–714 (2009).

    ADS  Article  Google Scholar 

  10. Żukowski, M., Zeilinger, A., Horne, M. A. & Ekert, A. K. ‘Event-ready-detectors’ Bell experiment via entanglement swapping. Phys. Rev. Lett. 71, 4287–4290 (1993).

    ADS  Article  Google Scholar 

  11. Rubenok, A., Slater, J. A., Chan, P., Lucio-Martinez, I. & Tittel, W. Real-world two-photon interference and proof-of-principle quantum key distribution immune to detector attacks. Phys. Rev. Lett. 111, 130501 (2013).

    ADS  Article  Google Scholar 

  12. Marcikic, I., De Riedmatten, H., Tittel, W., Zbinden, H. & Gisin, N. Long-distance teleportation of qubits at telecommunication wavelengths. Nature 421, 509–513 (2003).

    ADS  Article  Google Scholar 

  13. de Riedmatten, H. et al. Long distance quantum teleportation in a quantum relay configuration. Phys. Rev. Lett. 92, 047904 (2004).

    ADS  Article  Google Scholar 

  14. Bussières, F. et al. Quantum teleportation from a telecom-wavelength photon to a solid-state quantum memory. Nat. Photon. 8, 775–778 (2014).

    ADS  Article  Google Scholar 

  15. Takesue, H. et al. Quantum teleportation over 100 km of fiber using highly efficient superconducting nanowire single-photon detectors. Optica 2, 832–835 (2015).

    ADS  Article  Google Scholar 

  16. Ma, X. S. et al. Experimental delayed-choice entanglement swapping. Nat. Phys. 8, 479–484 (2012).

    Article  Google Scholar 

  17. Megidish, E. et al. Entanglement swapping between photons that have never coexisted. Phys. Rev. Lett. 110, 210403 (2013).

    ADS  Article  Google Scholar 

  18. Massar, S. & Popescu, S. Optimal extraction of information from finite quantum ensembles. Phys. Rev. Lett. 74, 1259–1263 (1995).

    ADS  MathSciNet  Article  Google Scholar 

  19. Lo, H.-K., Ma, X. & Chen, K. Decoy state quantum key distribution. Phys. Rev. Lett. 94, 230504 (2005).

    ADS  Article  Google Scholar 

  20. Wang, X. B. Beating the photon-number-splitting attack in practical quantum cryptography. Phys. Rev. Lett. 94, 230503 (2005).

    ADS  Article  Google Scholar 

  21. Sinclair, N. et al. Spectral multiplexing for scalable quantum photonics using an atomic frequency comb quantum memory and feed-forward control. Phys. Rev. Lett. 113, 053603 (2014).

    ADS  Article  Google Scholar 

  22. Krovi, H. et al. Practical quantum repeaters with parametric down-conversion sources. Appl. Phys. B 122, 52 (2016).

    ADS  Article  Google Scholar 

  23. Thiel, C. W., Sinclair, N., Tittel, W. & Cone, R. L. Optical decoherence studies of Tm3+ : Y3Ga5O12 . Phys. Rev. B 90, 214301 (2014).

    ADS  Article  Google Scholar 

  24. Valivarthi, R. et al. Efficient Bell state analyzer for time-bin qubits with fast-recovery WSi superconducting single photon detectors. Opt. Express 22, 24497–24506 (2014).

    ADS  Article  Google Scholar 

  25. Wavelength References Data Sheets and Pkg Drawings;

  26. Braunstein, S. L. & Pirandola, S. Side-channel-free quantum key distribution. Phys. Rev. Lett. 108, 130502 (2012).

    ADS  Article  Google Scholar 

  27. Sun, Q.-C. et al. Quantum teleportation with independent sources and prior entanglement distribution over a network. Nat. Photon. (2016).

  28. Brendel, J., Gisin, N., Tittel, W. & Zbinden, H. Pulsed energy-time entangled twin-photon source for quantum communication. Phys. Rev. Lett. 82, 2594–2597 (1999).

    ADS  Article  Google Scholar 

  29. Marsili, F. et al. Detecting single infrared photons with 93% system efficiency. Nat. Photon. 7, 210–214 (2013).

    ADS  Article  Google Scholar 

  30. 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).

    ADS  Article  Google Scholar 

Download references


The authors thank T. Andruschak, R. Angelo, D. Basto, C. Chambers and H. Dhillon from the City of Calgary for providing access to the fibre network and for help during the experiment, V. Kiselyov for technical support and P. Lefebvre for help with aligning the entangled photon pair source. This work was funded through Alberta Innovates Technology Futures (AITF), the National Science and Engineering Research Council of Canada (NSERC) and the Defense Advanced Research Projects Agency (DARPA) Quiness programme (contract no. W31P4Q-13-l-0004). W.T. also acknowledges funding as a Senior Fellow of the Canadian Institute for Advanced Research (CIFAR), and V.B.V. and S.W.N. acknowledge partial funding for detector development from the Defense Advanced Research Projects Agency (DARPA) Information in a Photon (InPho) programme. Part of the detector research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Author information

Authors and Affiliations



The SNSPDs were fabricated and tested by V.B.V., F.M., M.D.S. and S.W.N. The experiment was conceived and guided by W.T. The set-up was developed, measurements were performed, and the data were analysed by R.V., M.G.P., Q.Z., G.H.A. and D.O. The manuscript was written by W.T., R.V., M.G.P., Q.Z., G.H.A. and D.O.

Corresponding author

Correspondence to Wolfgang Tittel.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 797 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Valivarthi, R., Puigibert, M., Zhou, Q. et al. Quantum teleportation across a metropolitan fibre network. Nature Photon 10, 676–680 (2016).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

Further reading


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