On the violation of Bell's inequality for all non-product quantum states

Abstract

We present an explicit reexamination of Gisin's 1991 original proof concerning the violation of Bell's inequality for any pure entangled state of two-particle systems. Given the relevance of Gisin's work, our analysis is motivated by pedagogical reasons and allows the straightening of a few mathematical points in the original proof that in no way change the physical conclusions reached by Gisin.

arXiv comment12 pages, no figures. We have added the following sentence in the arXiv-version (Section named: Background): The following background discussion follows very closely the presentation presented by Asher Peres in Ref. [13]. Ref. [13] (together with References [1], [14], and [16]) by Asher Peres was already present in the published version of our manuscript