Modified quantum delayed-choice experiment without quantum control

TL;DR

This paper introduces a modified quantum delayed-choice experiment that observes wave-particle superpositions without quantum control or entanglement, enabling device-independent tests and exploring nonlocality in single photons.

Contribution

It proposes a new scheme for wave-particle superposition and nonlocality tests without quantum control, extending to multiple degrees of freedom and entanglement.

Findings

Demonstrates violation of classical hidden variable models

Allows observation of wave-particle morphing behavior

Extends to two degrees of freedom and single-photon entanglement

Abstract

Wheeler's delayed-choice experiment delays the decision to observe either the wave or particle behavior of a photon until after it has entered the interferometer, and the quantum delayed-choice experiment provides the possibility of observing the wave and particle behavior simultaneously by introducing quantum control device. We here propose a modified quantum delayed-choice experiment without quantum control or entanglement assistance, in which a photon can be prepared in a wave-particle superposition state and the morphing behavior of wave-to-particle transition can be observed easily. It is demonstrated that the presented scheme can allow us to rule out classical hidden variable models in a device-independent manner via violating dimension witness. We also extend the scheme to the situation of two degrees of freedom, first constructing a hybrid quantum delayed-choice experiment which enables simultaneous observation of a photon's wave and particle behaviors in different degrees of freedom, and then proposing a scheme to prepare the single-photon wave-particle entanglement. This study is not only meaningful to explore the wave and particle properties of photons, but also provides potential for the research of the single-particle nonlocality from the perspective of the wave-particle degree of freedom.