Journal Article

Exotic looped trajectories of photons in three-slit interference

Safari, Akbar, Magaña-Loaiza, Omar S, Banzer, Peter, Leuchs, Gerd, Fickler, Robert, Mick, Uwe, Rodenburg, Brandon, Boyd, Robert W., De Leon, Israel, Mirhosseini, Mohammad, McIntyre, Brian

2016

Overview

The validity of the superposition principle and of Born’s rule are well-accepted tenants of quantum mechanics. Surprisingly, it has been predicted that the intensity pattern formed in a three-slit experiment is seemingly in contradiction with the most conventional form of the superposition principle when exotic looped trajectories are taken into account. However, the probability of observing such paths is typically very small, thus rendering them extremely difficult to measure. Here we confirm the validity of Born’s rule and present the first experimental observation of exotic trajectories as additional paths for the light by directly measuring their contribution to the formation of optical interference fringes. We accomplish this by enhancing the electromagnetic near-fields in the vicinity of the slits through the excitation of surface plasmons. This process increases the probability of occurrence of these exotic trajectories, demonstrating that they are related to the near-field component of the photon’s wavefunction. Looped trajectories of photons in a three-slit interference experiment could modify the resulting intensity pattern, but they are experimentally hard to observe. Here the authors exploit surface plasmon excitations to increase their probability, measuring their contribution and confirming Born’s rule.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 132/122 / 639/624/400/482 / 639/766/483/1139 / 639/766/483/3925 / Boundary conditions / Experiments / Humanities and Social Sciences / multidisciplinary / Photonics / Probability / Propagation / Science / Science (multidisciplinary)