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Experimental extraction of an entangled photon pair from two identically decohered pairs

Abstract

Entanglement is considered to be one of the most important resources in quantum information processing schemes, including teleportation1,2,3, dense coding4 and entanglement-based quantum key distribution5. Because entanglement cannot be generated by classical communication between distant parties, distribution of entangled particles between them is necessary. During the distribution process, entanglement between the particles is degraded by the decoherence and dissipation processes that result from unavoidable coupling with the environment. Entanglement distillation and concentration schemes6,7,8,9 are therefore needed to extract pairs with a higher degree of entanglement from these less-entangled pairs; this is accomplished using local operations and classical communication. Here we report an experimental demonstration of extraction of a polarization-entangled photon pair from two decohered photon pairs. Two polarization-entangled photon pairs are generated by spontaneous parametric down-conversion and then distributed through a channel that induces identical phase fluctuations to both pairs; this ensures that no entanglement is available as long as each pair is manipulated individually. Then, through collective local operations and classical communication we extract from the two decohered pairs a photon pair that is observed to be polarization-entangled.

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References

  1. 1

    Bennett, C. H. et al. Teleporting an unknown quantum state via dual classical and Einstein-Podolsky-Rosen channels. Phys. Rev. Lett. 70, 1895–1898 (1993)

  2. 2

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

  3. 3

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

  4. 4

    Bennett, C. H. & Wiesner, S. J. Communication via one- and two-particle operators on Einstein-Podolsky-Rosen states. Phys. Rev. Lett. 69, 2881–2884 (1992)

  5. 5

    Ekert, A. K. Quantum cryptography based on Bell's theorem. Phys. Rev. Lett. 67, 661–663 (1991)

  6. 6

    Bennett, C. H., Bernstein, H. J., Popescu, S. & Schumacher, B. Concentrating partial entanglement by local operations. Phys. Rev. A 53, 2046–2052 (1996)

  7. 7

    Bennett, C. H., DiVincenzo, D. P., Smolin, J. A. & Wootters, W. K. Mixed-state entanglement and quantum error correction. Phys. Rev. A 54, 3824–3851 (1996)

  8. 8

    Bennett, C. H. et al. Purification of noisy entanglement and faithful teleportation via noisy channels. Phys. Rev. Lett. 76, 722–725 (1996)

  9. 9

    Deutsch, D. et al. Quantum privacy amplification and the security of quantum cryptography over noisy channels. Phys. Rev. Lett. 77, 2818–2821 (1996)

  10. 10

    Bose, S., Vedral, V. & Knight, P. L. Purification via entanglement swapping and conserved entanglement. Phys. Rev. A 60, 194–197 (1999)

  11. 11

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

  12. 12

    Yamamoto, T., Koashi, M. & Imoto, N. Concentration and purification scheme for two partially entangled photon pairs. Phys. Rev. A 64, 012304 (2001)

  13. 13

    Zhao, Z., Pan, J.-W. & Zhan, M. S. Practical scheme for entanglement concentration. Phys. Rev. A 64, 014301 (2001)

  14. 14

    Kwiat, P. G., Barraza-Lopez, S., Stefanov, A. & Gisin, N. Experimental entanglement distillation and ‘hidden’ non-locality. Nature 409, 1014–1017 (2001)

  15. 15

    Kwiat, P. G. et al. Ultrabright source of polarization-entangled photons. Phys. Rev. A 60, R773–R776 (1999)

  16. 16

    Kim, Y. H., Kulik, S. P. & Shih, Y. High-intensity pulsed source of space-time and polarization double-entangled photon pairs. Phys. Rev. A 62, 011802 (2000)

  17. 17

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

  18. 18

    Bouwmeester, D. et al. Observation of three-photon Greenberger-Horne-Zeilinger entanglement. Phys. Rev. Lett. 82, 1345–1349 (1999)

  19. 19

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

  20. 20

    Jennewein, T., Weihs, G., Pan, J.-W. & Zeilinger, A. Experimental nonlocality proof of quantum teleportation and entanglement swapping. Phys. Rev. Lett. 88, 017903 (2002)

  21. 21

    Lamas-Linares, A., Howell, J. C. & Bouwmeester, D. Stimulated emission of polarization-entangled photons. Nature 412, 887–890 (2001)

  22. 22

    Zukowski, M., Zeilinger, A. & Weinfurter, H. Entangling photons radiated by independent pulsed sources. Ann. NY Acad. Sci. 755, 91–102 (1995)

  23. 23

    Rarity, J. G. Interference of single photons from separate sources. Ann. NY Acad. Sci. 755, 624–631 (1995)

  24. 24

    Özdemir, Ş. K., Miranowicz, A., Koashi, M. & Imoto, N. Pulse mode projection synthesis: Effects of mode mismatch on optical state truncation and preparation. Phys. Rev. A 66, 053809 (2002)

  25. 25

    Nagata, K., Koashi, M. & Imoto, N. Observables suitable for restricting the fidelity to multipartite maximally entangled states. Phys. Rev. A 65, 042314 (2002)

  26. 26

    Pittman, T. B., Jacobs, B. C. & Franson, J. D. Probabilistic quantum logic operations using polarizing beam splitters. Phys. Rev. A 64, 062311 (2001)

  27. 27

    Pittman, T. B., Jacobs, B. C. & Franson, J. D. Demonstration of nondeterministic quantum logic operations using linear optical elements. Phys. Rev. Lett. 88, 257902 (2002)

  28. 28

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

  29. 29

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

  30. 30

    Koashi, M., Yamamoto, T. & Imoto, N. Probabilistic manipulation of entangled photons. Phys. Rev. A 63, 030301 (2001)

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Acknowledgements

We thank K. Nagata, K. Tamaki, A. Miranowicz and J. Shimamura for helpful discussions.

Author information

Correspondence to Nobuyuki Imoto.

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The authors declare that they have no competing financial interests.

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Figure 1: The schematic diagram of our experiment.
Figure 2: Experimental set-up for the polarization-entangled photon-pair source.
Figure 3: Experimental results showing that PPC decoheres individual pairs.
Figure 4: Experimental results showing that the extracted photon pair is entangled.

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