Some time ago the Raymond Chiao Team at the University at Berkley performed an experiment to test if using polarity to identify the route for a photon would dissolve an interference pattern. In the original experiment photons were split in two by a down converter and then directed by mirrors to converge at a beam splitter and then by mirrors to a detector. When a polarizing shifter was placed in only one path just after the down converter ( photon tagging ) the pattern dissolved. When polarizing filters were placed just after the beam splitter on both paths ( quantum erasing ) the pattern was restored. Later, one of the original architects of the experiment, Marland Scully of the University of New Mexico, suggested a variation in which the polarizing shifters were replaced by polarizing beam splitters. The Chao Team found that when the photons from all four paths were detected together there was no interference patten. However, when, and only when, the detection was segregated into groups containing only photon paths that would produce the same polarity, interference patterns emerged. This seemed to contradict quantum theory expectations. Marland Scully gave the effect a name, " Medieval Necromancy ". My question is: does anyone know if over the passing years there has been an explanation compatible with quantum theory put forward to explain this supposed anomaly?
