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Quantum Information

Source of triggered entangled photon pairs? (Reply)

Nature volume 445, pages E5–E6 (2007)Cite this article

Abstract

We have reported triggered photon-pair emission from single quantum dots that is suggestive of polarization entanglement1. Gilchrist et al.2 criticize our analysis of the density matrix, claiming that the entanglement test is inappropriate. However, we show here that this analysis is in fact valid for an unpolarized source such as ours, and that this analysis (as well as alternative measures of entanglement) suggests that quantum-dot sources do emit entangled photons, and that their quality is rapidly improving3.

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Figure 1: Measurements showing that emission is unpolarized, within error.

References

  1. Stevenson, R. M. et al. Nature 439, 179–182 (2006).

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  2. Gilchrist, A., Resch, K. J. & White, A. G. Nature 445, doi: 10.1038/nature05546 (2007).

  3. Young, R. J. et al. N. J. Physics 8, 29 (2006).

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  4. Edamatsu, K., Oohata, G., Shimizu, R. & Itoh, T. Nature 431, 167–170 (2004).

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Authors and Affiliations

  1. Toshiba Research Europe, 260 Cambridge Science Park, Cambridge, CB4 0WE, UK

    R. Mark Stevenson, Robert J. Young & Andrew J. Shields

  2. Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK

    Robert J. Young, Paola Atkinson, Ken Cooper & David A. Ritchie

Authors
  1. R. Mark Stevenson
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  2. Robert J. Young
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  3. Paola Atkinson
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  4. Ken Cooper
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  5. David A. Ritchie
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  6. Andrew J. Shields
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Corresponding author

Correspondence to R. Mark Stevenson.

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Cite this article

Stevenson, R., Young, R., Atkinson, P. et al. Source of triggered entangled photon pairs? (Reply). Nature 445, E5–E6 (2007). https://doi.org/10.1038/nature05547

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