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Quantum teleportation over 143 kilometres using active feed-forward


The quantum internet1 is predicted to be the next-generation information processing platform, promising secure communication2,3 and an exponential speed-up in distributed computation2,4. The distribution of single qubits over large distances via quantum teleportation5 is a key ingredient for realizing such a global platform. By using quantum teleportation, unknown quantum states can be transferred over arbitrary distances to a party whose location is unknown. Since the first experimental demonstrations of quantum teleportation of independent external qubits6, an internal qubit7 and squeezed states8, researchers have progressively extended the communication distance. Usually this occurs without active feed-forward of the classical Bell-state measurement result, which is an essential ingredient in future applications such as communication between quantum computers. The benchmark for a global quantum internet is quantum teleportation of independent qubits over a free-space link whose attenuation corresponds to the path between a satellite and a ground station. Here we report such an experiment, using active feed-forward in real time. The experiment uses two free-space optical links, quantum and classical, over 143 kilometres between the two Canary Islands of La Palma and Tenerife. To achieve this, we combine advanced techniques involving a frequency-uncorrelated polarization-entangled photon pair source, ultra-low-noise single-photon detectors and entanglement-assisted clock synchronization. The average teleported state fidelity is well beyond the classical limit9 of two-thirds. Furthermore, we confirm the quality of the quantum teleportation procedure without feed-forward by complete quantum process tomography. Our experiment verifies the maturity and applicability of such technologies in real-world scenarios, in particular for future satellite-based quantum teleportation.

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Figure 1: Quantum teleportation between the Canary Islands La Palma and Tenerife over both quantum and classical 143-km free-space channels.
Figure 2: State tomography results of the four quantum states without feed-forward over the 143-km free-space channel with the BSM outcome of | Ψ12.
Figure 3: Summary of the state fidelity results for the teleported quantum states with and without feed-forward.
Figure 4: Quantum process tomography of quantum teleportation without feed-forward.


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

    Article  ADS  CAS  Google Scholar 

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

    MATH  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  4. Ladd, T. D. et al. Quantum computers. Nature 464, 45–53 (2010)

    Article  ADS  CAS  Google Scholar 

  5. 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)

    Article  ADS  MathSciNet  CAS  Google Scholar 

  6. Bouwmeester, D. et al. Experimental quantum teleportation. Nature 390, 575–579 (1997)

    Article  ADS  CAS  Google Scholar 

  7. Boschi, D., Branca, S., De Martini, F., Hardy, L. & Popescu, S. Experimental realization of teleporting an unknown pure quantum state via dual classical and Einstein-Podolsky-Rosen channels. Phys. Rev. Lett. 80, 1121–1125 (1998)

    Article  ADS  MathSciNet  CAS  Google Scholar 

  8. Furusawa, A. et al. Unconditional quantum teleportation. Science 282, 706–709 (1998)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  MathSciNet  CAS  Google Scholar 

  10. Hughes, R. J. et al. Free-space quantum key distribution in daylight. J. Mod. Opt. 47, 549–562 (2000)

    Article  ADS  MathSciNet  Google Scholar 

  11. Rarity, J. G., Tapster, P. R., Gorman P. M & Knight, P. Ground to satellite secure key exchange using quantum cryptography. N. J. Phys. 4, 82 (2002)

    Article  Google Scholar 

  12. Aspelmeyer, M. et al. Long-distance free-space distribution of quantum entanglement. Science 301, 621–623 (2003)

    Article  ADS  CAS  Google Scholar 

  13. Marcikic, I., Lamas-Linares, A. & Kurtsiefer, C. Free-space quantum key distribution with entangled photons. Appl. Phys. Lett. 89, 101122 (2006)

    Article  ADS  Google Scholar 

  14. Ursin, R. et al. Entanglement-based quantum communication over 144 km. Nature Phys. 3, 481–486 (2007)

    Article  ADS  CAS  Google Scholar 

  15. Villoresi, P. et al. Experimental verification of the feasibility of a quantum channel between space and Earth. N. J. Phys. 10, 033038 (2008)

    Article  Google Scholar 

  16. Fedrizzi, A. et al. High-fidelity transmission of entanglement over a high-loss free-space channel. Nature Phys. 5, 389–392 (2009)

    Article  ADS  CAS  Google Scholar 

  17. Scheidl, T. et al. Feasibility of 300 km quantum key distribution with entangled states. N. J. Phys. 11, 085002 (2009)

    Article  Google Scholar 

  18. Jin, X.-M. et al. Experimental free-space quantum teleportation. Nature Photon. 4, 376–381 (2010)

    Article  ADS  CAS  Google Scholar 

  19. Scheidl, T. et al. Violation of local realism with freedom of choice. Proc. Natl Acad. Sci. USA 107, 19708–19713 (2010)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  21. Ursin, R. et al. Quantum teleportation across the Danube. Nature 430, 849 (2004)

    Article  ADS  CAS  Google Scholar 

  22. Briegel, H.-J., Dür, W., Cirac, J. I. & Zoller, P. Quantum repeaters: the role of imperfect local operations in quantum communication. Phys. Rev. Lett. 81, 5932–5935 (1998)

    Article  ADS  CAS  Google Scholar 

  23. Einstein, A., Podolsky, B. & Rosen, N. Can quantum-mechanical description of physical reality be considered complete? Phys. Rev. 47, 777–780 (1935)

    Article  ADS  CAS  Google Scholar 

  24. Kwiat, P. G. et al. New high-intensity source of polarization-entangled photon pairs. Phys. Rev. Lett. 75, 4337–4341 (1995)

    Article  ADS  CAS  Google Scholar 

  25. Calsamiglia, J. & Lütkenhaus, N. Maximum efficiency of a linear-optical Bell-state analyzer. Appl. Phys. B 72, 67–71 (2001)

    Article  ADS  CAS  Google Scholar 

  26. Kim, Y.-H., Kulik, S. P., Chekhova, M. V., Grice, W. P. & Shih, Y. Experimental entanglement concentration and universal Bell-state synthesizer. Phys. Rev. A 67, 010301(R) (2003)

    Article  ADS  Google Scholar 

  27. Poh, H. S., Lim, J., Marcikic, I., Lamas-Linares, A. & Kurtsiefer, C. Eliminating spectral distinguishability in ultrafast spontaneous parametric down-conversion. Phys. Rev. A 80, 043815 (2009)

    Article  ADS  Google Scholar 

  28. Yao, X.-C. et al. Observation of eight-photon entanglement. Nature Photon. 6, 225–228 (2012)

    Article  ADS  CAS  Google Scholar 

  29. Kim, Y.-S., Jeong, Y.-C., Sauge, S., Makarov, V. & Kim, Y.-H. Ultra-low noise single-photon detector based on Si avalanche photodiode. Rev. Sci. Instrum. 82, 093110 (2011)

    Article  ADS  Google Scholar 

  30. White, A. G., James, D. F. V., Eberhard, P. H. & Kwiat, P. G. Nonmaximally entangled states: production, characterization, and utilization. Phys. Rev. Lett. 83, 3103–3107 (1999)

    Article  ADS  CAS  Google Scholar 

  31. 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)

    Article  ADS  Google Scholar 

  32. Aspelmeyer, M., Jennewein, T., Pfennigbauer, M., Leeb, W. R. & Zeilinger, A. Long-distance quantum communication with entangled photons using satellites. IEEE J. Sel. Top. Quantum Electron. 9, 1541–1551 (2003)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

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We thank the staff of IAC: F. Sanchez-Martinez, A. Alonso, C. Warden, M. Serra and J. Carlos; and the staff of ING: M. Balcells, C. Benn, J. Rey, O. Vaduvescu, A. Chopping, D. González, S. Rodríguez, M. Abreu, L. González; J. Kuusela, E. Wille and Z. Sodnik; and J. Perdigues of the OGS and ESA. X.-S.M., T.J., R.U. and A.Z. thank S. Ramelow for discussions, P. Kolenderski for discussions on the SPDC source with the Bell-state synthesizer, S. Zotter for help during the early stages of the experiment, and R. Steinacker for meteorological advice. J.K. was supported by the EU project MALICIA. E.A. and V.M. thank C. Kurtsiefer and Y.-S. Kim for detector electronics design, J. Skaar for support, and the Research Council of Norway (grant No. 180439/V30) and Industry Canada for support. This work was made possible by grants from the European Space Agency (contract 4000104180/11/NL/AF), the Austrian Science Foundation (FWF) under projects SFB F4008 and CoQuS, and the FFG for the QTS project (no. 828316) within the ASAP 7 program. We also acknowledge support by the European Commission, grant Q-ESSENCE (no. 248095) and the John Templeton Foundation.

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Authors and Affiliations



X.-S.M. conceived the research, designed and carried out the experiment, and analysed data. T.H., T.S. and D.W. carried out the experiment and analysed data. S.K., W.N., B.W. and A.M. provided experimental assistance during the early stage of the experiment. J.K. provided the theoretical analysis and analysed data. E.A. and V.M. developed the ultra-low-noise detectors. T.J. provided experimental and conceptual assistance, and conceived and developed the coincidence analysis code. R.U. conceived the research, planned and carried out the experiment and analysed data. A.Z. defined the scientific goals, conceived the research, designed the experiment and supervised the project. X.-S.M., T.H., T.S., J.K., R.U. and A.Z. wrote the manuscript with assistance from all other co-authors.

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Correspondence to Xiao-Song Ma or Anton Zeilinger.

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The authors declare no competing financial interests.

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Ma, XS., Herbst, T., Scheidl, T. et al. Quantum teleportation over 143 kilometres using active feed-forward. Nature 489, 269–273 (2012).

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