Experimental Realization of Hyper-Entangled Two-Photon States

Yoon-Ho Kim

Cinelli, C., Marco Barbieri, F. De Martini +1 more

We report on the the experimental realization of hyper-entangled two photon states, entangled in polarization and momentum. These states are produced by a high brilliance parametric source of entangled photon pairs with peculiar characteristics of flexibility in terms of state generation. The quality of the entanglement in the two degrees of freedom has been tested by multimode Hong-Ou-Mandel interferometry.

Phillip F. Schewe

Marco Barbieri, Claudia Cinelli, F. De Martini +1 more

We report the experimental realization and the characterization of polarization and momentum hyper-entangled two photon states, generated by a new parametric source of correlated photon pairs. By adoption of these states a successful ''all versus nothing'' test of quantum mechanics was performed. The two photon hyper-entangled states are expected to find at an increasing rate a widespread application in state engineering and quantum information. PACS: 03.67.-a, 03.67.Mn, 03.67.Hk, 42.65. Lm

Yanhua H. Shih

Paul G. Kwiat

Entangled states are key ingredients to the new field of quantum information, including quantum dense coding, teleportation, and computation. However, only a relatively small class of entangled states has been investigated experimentally, or even discussed extensively. In particular, efforts to date have focused on two particles entangled in a single degree of freedom, for example polarization, or energy, or momentum direction. Novel phase-matching arrangements in spontaneous parametric down-conversion allow the preparation of pairs of photons that are simultaneously entangled in all of these. We shall call such a multiply-entangled state ‚hyper-entangled‘. In addition, an even more general state–-a non-maximally entangled state–-should be realizable, in which the amplitudes of the contributing terms are not equal.