Bounds for the Distance Dependence of Correlation Functions of Entangled   Photons in Waveguides
  The distance dependence of the probability of observing two photons in a waveguide is investigated. The Glauber correlation functions of the entangled photons in waveguides are considered and the spatial and temporal dependence of the correlation functions is evaluated. We derive upper bounds to the distance dependence of the probability of observing two photons. These inequalities should be possible to observe in experiments. 
Andrei Khrennikov, Borje Nilsson, Sven Nordebo, Igor Volovich
quant-ph math-ph math.MP