Exploring Macroscopic Entanglement with a Single Photon and Coherent States

TL;DR

This paper presents a simple method using displacement operations and photon detection to create and reveal macroscopic entanglement between a single photon and coherent states, facilitating exploration of quantum phenomena at larger scales.

Contribution

The authors introduce a practical approach combining displacement and photon detection to observe macroscopic entanglement, advancing experimental techniques in quantum optics.

Findings

Preliminary experimental results demonstrate feasibility.

Method can explore entanglement from one to a thousand photons.

Provides insights into quantum features in macroscopic systems.

Abstract

Entanglement between macroscopically populated states can easily be created by combining a single photon and a bright coherent state on a beam-splitter. Motivated by the simplicity of this technique, we report on a method using displacement operations in the phase space and basic photon detections to reveal such an entanglement. We demonstrate through preliminary experimental results, that this eminently feasible approach provides an attractive way for exploring entanglement at various scales, ranging from one to a thousand photons. This offers an instructive viewpoint to gain insight into the reasons that make it hard to observe quantum features in our macroscopic world.