Hyperentanglement of two photons in three degrees of freedom
Abstract
A six-qubit hyperentangled state has been realized by entangling two photons in three degrees of freedom. These correspond to the polarization, the longitudinal momentum, and the indistinguishable emission produced by a two-crystal system operating with type I phase matching in the spontaneous parametric down conversion regime. The state has been characterized by a chained interferometric apparatus and its complete entangled nature has been tested by a witness criterion specifically presented for hyperentangled states. The experiment represents a realization of a genuine hyperentangled state with the maximum entanglement between the two particles allowed in the given 23×23 Hilbert space.
- Publication:
-
Physical Review A
- Pub Date:
- March 2009
- DOI:
- 10.1103/PhysRevA.79.030301
- arXiv:
- arXiv:0810.4461
- Bibcode:
- 2009PhRvA..79c0301V
- Keywords:
-
- 03.67.Bg;
- 42.50.Dv;
- 42.65.Lm;
- Entanglement production and manipulation;
- Nonclassical states of the electromagnetic field including entangled photon states;
- quantum state engineering and measurements;
- Parametric down conversion and production of entangled photons;
- Quantum Physics
- E-Print:
- 4 pages, 2 figures, Revtex4