The symmetrization postulate asserts that the state of particular species of particles can only be of one permutation symmetry type: symmetric for bosons and antisymmetric for fermions. We report some experimental results showing that pairs of photons indistinguishable by all degrees of freedom can exhibit not only a bosonic behavior, as expected for photons, but also a surprisingly sharp fermionic behavior under speci c conditions.
At what level of energy does a classical experiment become quantum mechanical? Where does classical electromagnetic theory apply and where do we have to turn to quantum optics? Is there a sharp line between these two models? And if so: why, and why at this level? Or if not: what are the common features of the formalisms, and what are the di erences? With our upcoming experimental work, we hope to be able to gain some insight into these challenging questions. The starting point is an investigation of the results from an ordinary Bell type experiment showing entanglement between two photons, where the photons has been generated using spontaneous parametric down conversion, and the same experiment but with a classical source where two highly attenuated pulses are combined. Here we will present in detail our planned experiment.