X-entanglement of PDC photon pairs
A. Gatti, Lucia Caspani, E. Brambilla, O. Jedrkiewicz, L.A. Lugiato · International Conference on Quantum Information · 2008
The X-wave picture is adopted to describe the spatio-temporal entanglement of PDC photons. Key elements of novelty are the non-factorability of the state and the extreme relative localization of photons in space and time.