Violation of a Bell inequality in two-dimensional orbital angular momentum state-spaces

J. Leach, B. Jack, J. Romero, M. Ritsch-Marte, R.W. Boyd, A.K. Jha, S.M. Barnett, S. Franke-Arnold, M.J. Padgett

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We observe entanglement between photons in controlled super-position states of orbital angular momentum (OAM). By drawing a direct analogy between OAM and polarization states of light, we demonstrate the entangled nature of high order OAM states generated by spontaneous downconversion through violation of a suitable Clauser Horne Shimony Holt (CHSH)-Bell inequality. We demonstrate this violation in a number of two-dimensional subspaces of the higher dimensional OAM Hilbert space.
Original languageEnglish
Pages (from-to)8287-8293
Number of pages7
JournalOptics Express
Issue number10
Publication statusPublished - 11 May 2009


  • hidden variable theories
  • local theories
  • light beams
  • entanglement

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