Abstract
We explore whether it is possible in principle to find the "circularity" (amount of circular polarization) of a single photon to a degree not allowed in conventional quantum theory. The thought experiment involves passing the same photon many times through a half-wave plate (with intermediate correction) so the tiny "spin" interaction of the photon is amplified enough to transfer measurable angular momentum to the detector HWP. HWPs invert coefficients for RH and LH states instead of "collapsing" the photon into a circular basis. Because passing one photon many times through a HWP should be like passing many photons once each though the plate, the transferred angular momentum would be revealed on a continuum. Such a measurement would violate the projection postulate (which says that only yes/no answers to probabilistic detection questions can be found for a single particle).
Neil Bates