Regular Article

Can nonclassical correlations survive in the presence of asymmetric lossy channels?^★

¹ Department of Science and High Technology, University of Insubria, Via Valleggio 11, 22100 Como, Italy
² Institute for Photonics and Nanotechnologies, CNR, Via Valleggio 11, 22100 Como, Italy

^a e-mail: alessia.allevi@uninsubria.it

Received: 30 July 2018
Received in final form: 23 August 2018
Published online: 11 October 2018

Abstract

Nonclassical correlations are a fundamental resource for applications involving multipartite systems. To assess nonclassicality, several different criteria can be applied to measured data. Here we compare three inequalities by applying them to a multi-mode twin-beam state, in which one of the two parties is transmitted through a varying lossy channel. We demonstrate, both theoretically and experimentally, that the asymmetry introduced by losses affects the three criteria in different ways, thus offering a tool for quantum optics applications.