Delayed Choice for Quantum Mechanics

S. Malin

Jeffrey H. Boyd

The publication in Science in 2007 of Jacques et al ``Experimental realization of Wheeler's delayed-choice gedanken experiment,'' appears to demonstrate many counter-intuitive ideas. The solidity of those conclusions depends on whether quantum mechanics (QM) provides the ONLY available explanation of the experiment. By thinking outside the box we have arrived at a different explanation of that experiment. QM is the box outside of which we think, not because of criticism of QM, but in order to explore an unconventional viewpoint. Our explanation is based on elementary waves. We find no delayed choice. What appears to be delayed choice is an illusion. We also find local cause and effect. This does not prove that our way of thinking is correct. It simply means that we propose an alternative explanation of the experiment that does not lead to all those counter-intuitive ideas.

Peter Shadbolt

Bram Gaasbeek

The delayed choice experiments are a collection of experiments where the counterintuitive laws of quantum mechanics are manifested in a very striking way. Although the delayed choice experiments can be very accurately described with the standard framework of quantum optics, a more didactical and intuitive explanation seems not to have been given so far. In this note, we fill that gap.

Sang-Bae Kim, Byoung Seung HAM

Quantum superposition is the cornerstone of quantum mechanics, where interference fringes originate in the self-interference of a single photon via indistinguishable photon characteristics. Wheeler's delayed-choice experiments have been extensively studied for the wave-particle duality over the last several decades to understand the complementarity theory of quantum mechanics. The heart of the delayed-choice quantum eraser is in the mutually exclusive quantum feature violating the cause-effect relation. Here, we experimentally demonstrate the quantum eraser using coherent photon pairs by the delayed choice of a polarizer placed out of the interferometer. Coherence solutions of the observed quantum eraser are derived from a typical Mach-Zehnder interferometer, where the violation of the cause-effect relation is due to selective measurements of basis choice.

Warner A. Miller, JOHN ARCHIBALD WHEELER