Non-classical paths in interference experiments

TL;DR

This paper investigates non-classical paths in quantum interference, showing they cause measurable deviations from traditional superposition, and proposes experiments to confirm their existence using the Feynman path integral formalism.

Contribution

It quantifies non-classical path contributions in interference experiments and proposes feasible experiments to directly observe these effects.

Findings

Non-classical paths significantly affect interference patterns.

Proposed three-slit experiments can confirm non-classical path contributions.

Feynman path integral formalism effectively models these effects.

Abstract

In a double slit interference experiment, the wave function at the screen with both slits open is not exactly equal to the sum of the wave functions with the slits individually open one at a time. The three scenarios represent three different boundary conditions and as such, the superposition principle should not be applicable. However, most well known text books in quantum mechanics implicitly and/or explicitly use this assumption which is only approximately true. In our present study, we have used the Feynman path integral formalism to quantify contributions from non-classical paths in quantum interference experiments which provide a measurable deviation from a naive application of the superposition principle. A direct experimental demonstration for the existence of these non-classical paths is hard. We find that contributions from such paths can be significant and we propose simple three-slit interference experiments to directly confirm their existence.