Schroedinger Cat: Entanglement test in a Micro-Macroscopic system

TL;DR

This paper demonstrates the creation of a macro-state of over 35,000 photons entangled with a single-photon micro-state, using optical amplification and local filtering to test quantum entanglement at a macroscopic scale.

Contribution

It introduces a novel method to generate and verify entanglement between a large photon-number macro-state and a micro-state using phase-covariant cloning and local filtering techniques.

Findings

Successfully generated a macro-state of 3.5 x 10^4 photons entangled with a single photon.

Demonstrated non-separability of the bipartite system through local filtering and positive operator valued measurement.

Established a new approach for testing quantum entanglement in micro-macro systems.

Abstract

A Macro-state consisting of N= 3.5 x 10^4 photons in a quantum superposition and entangled with a far apart single-photon state (Micro-state) is generated. Precisely, an entangled photon pair is created by a nonlinear optical process, then one photon of the pair is injected into an optical parametric amplifier (OPA) operating for any input polarization state, i.e. into a phase-covariant cloning machine. Such transformation establishes a connection between the single photon and the multi particle fields. We then demonstrate the non-separability of the bipartite system by adopting a local filtering technique within a positive operator valued measurement.