A polarized photon with well-defined orbital angular momentum that emerges from a Mach-Zehnder interferometer (MZI) is shown to circumvent wave-particle duality. Its polarization-resolved detection probability forms a non-sinusoidal interferometric pattern. For certain phase differences between the MZI arms, this pattern yields both reliable which-path information and high phase-sensitivity.
@article{arxiv.0705.4038,
title = {Single-photon interferometry with orbital angular momentum circumvents standard wave-particle duality},
author = {M. Kolar and T. Opatrny and G. Kurizki},
journal= {arXiv preprint arXiv:0705.4038},
year = {2007}
}