Quantum delayed "choice" based on vectorially structured photon

TL;DR

This paper introduces a novel quantum delayed choice experiment using a single photon's polarization state, demonstrating the photon’s behavior morphing between wave and particle characteristics, challenging classical causality and deepening understanding of quantum complementarity.

Contribution

It proposes a new QDC experiment leveraging the photon’s quantum state itself, bypassing traditional control devices, and explores the morphing wave-particle behavior to challenge classical notions.

Findings

Photon's state can be tailored into arbitrary superpositions.

Photon exhibits morphing between wave and particle behaviors.

Deepens understanding of Bohr's complementarity principle.

Abstract

Whether a photon exhibits wavelike or particlelike behaviour depends on the observation method, as clearly demonstrated by Wheeler's delayed choice (DC) experiments. A key aspect of such experiments is the random determination of the observation device's status, typically controlled by a random number generator or a quantum-controlling apparatus. Here, we propose a novel version of the quantum delayed choice (QDC) experiment by tailoring the quantum state of the single photon into an arbitrary polarization superposition. In this experiment, the "choice" can be considered as being made by the photon's state itself at the moment of observation, thereby violating classical causality. Additionally, we observe the morphing behaviour of the single photon between wavelike and particlelike characteristics, which challenges the classical picture of waves and particles. Utilizing the quantum state of the photon rather than the quantum-controlling devices not only facilitates the implementation of the QDC experiment but also helps deepen the understanding of Bohr's complementarity principle.