Realization of the Einstein-Podolsky-Rosen paradox using momentum- and position-entangled photons from spontaneous parametric down conversion

Phys Rev Lett. 2004 May 28;92(21):210403. doi: 10.1103/PhysRevLett.92.210403. Epub 2004 May 28.


We report on a momentum-position realization of the EPR paradox using direct detection in the near and far fields of the photons emitted by collinear type-II phase-matched parametric down conversion. Using this approach we achieved a measured two-photon momentum-position variance product of 0.01 variant Planck's over 2pi (2), which dramatically violates the bounds for the EPR and separability criteria.