### Abstract

Language | English |
---|---|

Article number | 103024 |

Number of pages | 12 |

Journal | New Journal of Physics |

Volume | 11 |

DOIs | |

Publication status | Published - 12 Oct 2009 |

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### Keywords

- quantum tomography
- photon pairs
- orbital angular momentum
- parametric down-conversion
- entanglement

### Cite this

*New Journal of Physics*,

*11*, [103024]. https://doi.org/10.1088/1367-2630/11/10/103024

}

*New Journal of Physics*, vol. 11, 103024. https://doi.org/10.1088/1367-2630/11/10/103024

**Precise quantum tomography of photon pairs with entangled orbital angular momentum.** / Jack, B.; Leach, J.; Ritsch, H.; Barnett, S.M.; Padgett, M.J.; Franke-Arnold, S.

Research output: Contribution to journal › Article

TY - JOUR

T1 - Precise quantum tomography of photon pairs with entangled orbital angular momentum

AU - Jack, B.

AU - Leach, J.

AU - Ritsch, H.

AU - Barnett, S.M.

AU - Padgett, M.J.

AU - Franke-Arnold, S.

PY - 2009/10/12

Y1 - 2009/10/12

N2 - We report a high fidelity tomographic reconstruction of the quantum state of photon pairs generated by parametric down-conversion with orbital angular momentum (OAM) entanglement. Our tomography method allows us to estimate an upper and lower bound for the entanglement between the down-converted photons. We investigate the two-dimensional state subspace defined by the OAM states ± and superpositions thereof, with =1, 2, ..., 30. We find that the reconstructed density matrix, even for OAMs up to around =20, is close to that of a maximally entangled Bell state with a fidelity in the range between F=0.979 and F=0.814. This demonstrates that, although the single count-rate diminishes with increasing , entanglement persists in a large dimensional state space.

AB - We report a high fidelity tomographic reconstruction of the quantum state of photon pairs generated by parametric down-conversion with orbital angular momentum (OAM) entanglement. Our tomography method allows us to estimate an upper and lower bound for the entanglement between the down-converted photons. We investigate the two-dimensional state subspace defined by the OAM states ± and superpositions thereof, with =1, 2, ..., 30. We find that the reconstructed density matrix, even for OAMs up to around =20, is close to that of a maximally entangled Bell state with a fidelity in the range between F=0.979 and F=0.814. This demonstrates that, although the single count-rate diminishes with increasing , entanglement persists in a large dimensional state space.

KW - quantum tomography

KW - photon pairs

KW - orbital angular momentum

KW - parametric down-conversion

KW - entanglement

U2 - 10.1088/1367-2630/11/10/103024

DO - 10.1088/1367-2630/11/10/103024

M3 - Article

VL - 11

JO - New Journal of Physics

T2 - New Journal of Physics

JF - New Journal of Physics

SN - 1367-2630

M1 - 103024

ER -