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.

  • Letter
  • Published:

Experimental realization of freely propagating teleported qubits


Quantum teleportation1 is central to quantum communication, and plays an important role in a number of quantum computation protocols2,3. Most information-processing applications of quantum teleportation include the subsequent manipulation of the qubit (the teleported photon), so it is highly desirable to have a teleportation procedure resulting in high-quality, freely flying qubits. In our previous teleportation experiment4, the teleported qubit had to be detected (and thus destroyed) to verify the success of the procedure. Here we report a teleportation experiment that results in freely propagating individual qubits. The basic idea is to suppress unwanted coincidence detection events by providing the photon to be teleported much less frequently than the auxiliary entangled pair. Therefore, a case of successful teleportation can be identified with high probability without the need actually to detect the teleported photon. The experimental fidelity of our procedure surpasses the theoretical limit required for the implementation of quantum repeaters5,6.

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

Access options

Buy this article

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

Figure 1: Diagrams showing the principles of the Innsbruck experiment and of achieving free propagation of teleported qubits.
Figure 2: Set-up for experimental demonstration of free propagation of teleported qubits.
Figure 3: Two typical experimental results for 45° teleportation.
Figure 4: Conditional fidelities and non-conditional fidelities obtained in 45° teleportation for different neutral filters.

Similar content being viewed by others


  1. Bennett, C. H. et al. Teleporting an unknown quantum state via dual classical and Einstein-Podolsky-Rosen channels. Phys. Rev. Lett. 83, 3081–3084 (1993)

    Article  ADS  MathSciNet  Google Scholar 

  2. Gottesman, D. & Chuang, I. L. Demonstrating the viability of universal quantum computation using teleportation and single-qubit operations. Nature 402, 390–393 (1999)

    Article  ADS  CAS  Google Scholar 

  3. Knill, E., Laflamme, R. & Milburn, G. J. A scheme for efficient quantum computation with linear optics. Nature 409, 46–52 (2001)

    Article  ADS  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  5. Briegel, H.-J., Duer, 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 

  6. Aschauer, H. & Briegel, H. J. Private entanglement over arbitrary distances, even using noisy apparatus. Phys. Rev. Lett. 88, 047902 (2002)

    Article  ADS  Google Scholar 

  7. Braunstein, S. L. & Kimble, H. J. A posteriori teleportation. Nature 394, 840–841 (1998)

    Article  ADS  CAS  Google Scholar 

  8. Bouwmeester, D. et al. Reply to “A posteriori teleportation”. Nature 394, 841 (1998)

    Article  ADS  Google Scholar 

  9. Kok, P. & Braunstein, S. L. Postselected versus nonpostselected quantum teleportation using parametric down-conversion. Phys. Rev. A 61, 042304 (2000)

    Article  ADS  MathSciNet  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  11. Kim, Y. H., Kulik, S. P. & Shih, Y. H. Quantum teleportation of a polarization state with a complete Bell state measurement. Phys. Rev. Lett. 86, 1370–1373 (2001)

    Article  ADS  CAS  Google Scholar 

  12. Grosshans, F. & Grangier, P. Quantum cloning and teleportation criteria for continuous quantum variables. Phys. Rev. A 64, R010301 (2001)

    Article  ADS  MathSciNet  Google Scholar 

  13. Rudolph, T. & Sanders, B. C. Requirement of optical coherence for continuous variable quantum teleportation. Phys. Rev. Lett. 88, 077903 (2001)

    Article  ADS  Google Scholar 

  14. Pan, J.-W. et al. Experimental demonstration of four-photon entanglement and high-fidelity teleportation. Phys. Rev. Lett. 86, 4435–4438 (2001)

    Article  ADS  CAS  Google Scholar 

  15. Pan, J.-W. & Zeilinger, A. Greenberger-Horne-Zeilinger-state analyzer. Phys. Rev. A 57, 2208–2211 (1998)

    Article  ADS  MathSciNet  CAS  Google Scholar 

  16. Jennewein, T., Weihs, G., Pan, J.-W. & Zeilinger, A. Experimental nonlocality proof of quantum teleportation and entanglement swapping. Phys. Rev. Lett. 88, 017093 (2002)

    Google Scholar 

  17. Kurtsiefer, C., Oberparleiter, M. & Weinfurter, H. High-efficiency entangled photon pair collection in type-II parametric fluorescence. Phys. Rev. A 64, 023802 (2001)

    Article  ADS  Google Scholar 

  18. Howell, J. C., Lamas-Linares, A. & Bouwmeester, D. Experimental violation of a spin-1 Bell inequality using maximally entangled four-photon states. Phys. Rev. Lett. 88, 030401 (2002)

    Article  ADS  Google Scholar 

  19. Bennett, C. H. et al. Purification of noisy entanglement, and faithful teleportation via noisy channel. Phys. Rev. Lett. 76, 1895–1898 (1996)

    Google Scholar 

  20. Pan, J.-W., Simon, C., Brukner, C. & Zeilinger, A. Entanglement purification for quantum communication. Nature 410, 1067–1070 (2001)

    Article  ADS  CAS  Google Scholar 

Download references


This work was supported by the Austrian Science Foundation (FWF), the TMR and the QuComm programmes of the European Commission and the Alexander von Humboldt Foundation.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Jian-Wei Pan.

Ethics declarations

Competing interests

The authors declare that they have no competing financial interests.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Pan, JW., Gasparoni, S., Aspelmeyer, M. et al. Experimental realization of freely propagating teleported qubits. Nature 421, 721–725 (2003).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


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.


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