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Quantum Information

Source of triggered entangled photon pairs?


Arising from: R. M. Stevenson et al. Nature 439, 179–182 (2006)10.1038/nature04446; Stevenson et al. reply

The realization of an entangled photon source will be of great importance in quantum information — for example, for quantum key distribution and quantum computation — and Stevenson et al.1 have described such a source. However, we show here that first, their source is not entangled; second, they use inappropriate entanglement indicators that rely on assumptions invalidated by their data; and third, their source has insignificant entanglement even after simulating subtraction of the significant quantity of background noise. We therefore find that the standard of proof required for a semiconductor source of triggered entangled photon pairs has not been met by Stevenson et al.1.

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Correspondence to Andrew G. White.

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Gilchrist, A., Resch, K. & White, A. Source of triggered entangled photon pairs?. Nature 445, E4–E5 (2007).

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