On Visibility in the Afshar Two-Slit Experiment

TL;DR

The paper critically analyzes Afshar's modified two-slit experiment, arguing that the commonly assumed relationship between visibility and which-way parameters does not apply, and thus the experiment does not violate Bohr's Complementarity Principle.

Contribution

It clarifies the inapplicability of the V-K relationship to Afshar's experiment, challenging claims that it violates quantum complementarity.

Findings

The V-K relationship does not apply to Afshar's setup.

Afshar's experiment does not violate Bohr's Complementarity Principle.

Misinterpretations arise from incorrect assumptions about visibility and which-way parameters.

Abstract

A modified version of Young's experiment by Shahriar Afshar indirectly reveals the presence of a fully articulated interference pattern prior to the post-selection of a particle in a "which-slit" basis. While this experiment does not constitute a violation of Bohr's Complementarity Principle as claimed by Afshar, both he and many of his critics incorrectly assume that a commonly used relationship between visibility parameter V and "which-way" parameter K has crucial relevance to his experiment. It is argued here that this relationship does not apply to this experimental situation and that it is wrong to make any use of it in support of claims for or against the bearing of this experiment on Complementarity.