Angular two-photon interference and angular two-qubit states

Phys Rev Lett. 2010 Jan 8;104(1):010501. doi: 10.1103/PhysRevLett.104.010501. Epub 2010 Jan 5.

Abstract

Using angular-position-orbital-angular-momentum entangled photons, we study angular two-photon interference in a scheme in which entangled photons are made to pass through apertures in the form of double angular slits, and using this scheme, we demonstrate an entangled two-qubit state that is based on the angular-position correlations of entangled photons. The entanglement of the two-qubit state is quantified in terms of concurrence. These results provide an additional means for preparing entangled quantum states for use in quantum information protocols.