Momentum-position realization of the Einstein-Podolsky-Rosen paradox

Abstract

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 downconversion. Using this approach we achieved a measured two-photon momentum-position variance product of $0.01{\hslash }^2$, which dramatically violates the bounds for the EPR and separability criteria.