Non-local geometric phase in two-photon interferometry
Anthony Martin, Olivier Alibart, Jean-Christophe Flesch, Joseph Samuel, Supurna Sinha, Sébastien Tanzilli, Anders Kastberg · Europhysics Letters (EPL) · 2012
We report the experimental observation of the non-local geometric phase in Hanbury Brown-Twiss polarized intensity interferometry.The experiment involves two independent, polarized, incoherent sources, illuminating two polarized detectors.Varying the relative polarization angle between the detectors introduces a geometric phase equal to half the solid angle on the Poincaré sphere traced out by a pair of single photons.Local measurements at either detector do not reveal the effect of the geometric phase, which appears only in the coincidence counts between the two detectors, showing a genuinely non-local effect.We show experimentally that coincidence rates of photon arrival times at separated detectors can be controlled by the two-photon geometric phase.This effect can be used for manipulating and controlling photonic entanglement.