Multiparty multilevel Greenberger-Horne-Zeilinger states
Abstract
A generalization to $n$ parts with different number of levels (all with the same parity) of the proof of nonlocality without inequalities of Greenberger, Horne, and Zeilinger (GHZ) is proposed. The aim of this generalization is to illustrate the basic ingredients of any GHZ-like proof in order to provide an operative definition of what is a GHZ state for multiparty multilevel quantum systems.