Photonic de Broglie wave interferometers

In the recently proposed photonic de Broglie wave interferometer, sophisticated beam splitters are used to split the de Broglie wave of a set of photons. The photonic de Broglie or collective phase shift can, however, be found in conventional interferometry if the full photon statistics are recorded. We propose a variation of the original photonic de Broglie wave interferometer. We show that the collective phase shift can and has been found in interferometry using photon pairs and propose two new photonic de Broglie wave interferometers in which normal beam splitters are used. Both of these rely on conditioning to select the cases for which all the photons behave as a single object.