Simultaneous observation of correlations in position-momentum and polarization variables
Marcelo Pereira de Almeida, Stephen Patrick Walborn, P. H. Souto Ribeiro · Physical Review A · 2006
We demonstrate experimentally that it is possible to prepare and detect photon pairs created by spontaneous parametric downconversion which exhibit simultaneous position-momentum and polarization correlations. We discuss the use of these correlations in several four-dimensional key distribution protocols.