Trajectory-based interpretation of Young's experiment, the Arago-Fresnel laws and the Poisson-Arago spot for photons and massive particles

TL;DR

This paper offers a trajectory-based interpretation of Young's experiment, the Arago-Fresnel laws, and the Poisson-Arago spot, aligning well with experimental observations for photons and massive particles, and emphasizing the role of energy density over 'which-way' information.

Contribution

It introduces a trajectory interpretation based on quantum probability current and Poynting vector, differing from traditional 'which-way' explanations, and matches experimental photon trajectory data.

Findings

Photon trajectories agree with experimental data.

Trajectory interpretation differs from 'which-way' explanations.

Distribution of trajectories reproduces the Poisson-Arago spot.

Abstract

We present a trajectory based interpretation for Young's experiment, the Arago-Fresnel laws and the Poisson-Arago spot. This approach is based on the equation of the trajectory associated with the quantum probability current density in the case of massive particles, and the Poynting vector for the electromagnetic field in the case of photons. Both the form and properties of the evaluated photon trajectories are in good agreement with the averaged trajectories of single photons observed recently in Young's experiment by Steinberg's group at the University of Toronto. In the case of the Arago-Fresnel laws for polarized light, the trajectory interpretation presented here differs from those interpretations based on the concept of "which-way" (or "which-slit") information and quantum erasure. More specifically, the observer's information about the slit that photons went through is not relevant to the existence of interference; what is relevant is the form of the electromagnetic energy density and its evolution, which will model consequently the distribution of trajectories and their topology. Finally, we also show that the distributions of end points of a large number of evaluated photon trajectories are in agreement with the distributions measured at the screen behind a circular disc, clearly giving rise to the Poisson-Arago spot.