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Generation of Hyperentangled Photons Pairs

Julio T. Barreiro·Nathan K. Langford·Nicholas A. Peters·Paul G. Kwiat
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Abstract

We experimentally demonstrate the first quantum system entangled in every degree of freedom (hyperentangled). Using pairs of photons produced in spontaneous parametric downconversion, we verify entanglement by observing a Bell-type inequality violation in each degree of freedom: polarization, spatial mode and time-energy. We also produce and characterize maximally hyperentangled states and novel states simultaneously exhibiting both quantum and classical correlations. Finally, we report the tomography of a 2x2x3x3 system (36-dimensional Hilbert space), which we believe is the first reported photonic entangled system of this size to be so characterized.

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Julio T. Barreiro, Nathan K. Langford, Nicholas A. Peters, Paul G. Kwiat. 2009-05-15. Generation of Hyperentangled Photons Pairs. https://doi.org/10.1103/physrevlett.95.260501

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