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.
@article{arxiv.0806.2218,
title = {Schroedinger Cat: Entanglement test in a Micro-Macroscopic system},
author = {Francesco De Martini and Fabio Sciarrino and Chiara Vitelli},
journal= {arXiv preprint arXiv:0806.2218},
year = {2009}
}