N-particle nonclassicality without N-particle correlations
Abstract
Most of known multipartite Bell inequalities involve correlation functions for all subsystems. They are useless for entangled states without such correlations. We give a method of derivation of families of Bell inequalities for N parties, which involve, e.g., only (N-1)-partite correlations, but still are able to detect proper N-partite entanglement. We present an inequality which reveals five-partite entanglement despite only four-partite correlations. Classes of inequalities introduced here can be put into a handy form of a single non-linear inequality. An example is given of an N qubit state, which strongly violates such an inequality, despite having no N-qubit correlations. This surprising property might be of potential value for quantum information tasks.
Cite
@article{arxiv.1112.0951,
title = {N-particle nonclassicality without N-particle correlations},
author = {Marcin Wieśniak and Mohamed Nawareg and Marek Żukowski},
journal= {arXiv preprint arXiv:1112.0951},
year = {2013}
}
Comments
5 pages