Which Way?

TL;DR

This experiment demonstrates simultaneous wave and particle behaviors of photons in a double-slit setup, challenging traditional interpretations and suggesting a wave-only perspective could explain quantum phenomena.

Contribution

It introduces a method to observe which-way information and interference simultaneously, providing new insights into wave-particle duality in quantum mechanics.

Findings

Successful imaging of slit paths while preserving interference

Photon wave and particle behaviors observed simultaneously

Supports a wave-only interpretation of quantum objects

Abstract

I report the result of a which-way experiment based on Young's double-slit experiment. It reveals which slit photons go through while retaining the (self) interference of all the photons collected. The idea is to image the slits using a lens with a narrow aperture and scan across the area where the interference fringes would be. The aperture is wide enough to separate the slits in the images, i.e., telling which way. The illumination pattern over the pupil is reconstructed from the series of slit intensities. The result matches the double-slit interference pattern well. As such, the photon's wave-like and particle-like behaviors are observed simultaneously in a straightforward and thus unambiguous way. The implication is far reaching. For one, it presses hard, at least philosophically, for a consolidated wave-and-particle description of quantum objects, because we can no longer dismiss such a challenge on the basis that the two behaviors do not manifest at the same time. A bold proposal is to forgo the concept of particles. Then, Heisenberg's uncertainty principle would be purely a consequence of waves without being ordained upon particles.