Nonlocality without inequalities has not been proved for maximally entangled states - art. no. 022119

Authors
Citation
A. Cabello, Nonlocality without inequalities has not been proved for maximally entangled states - art. no. 022119, PHYS REV A, 6102(2), 2000, pp. 2119
Citations number
15
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW A
ISSN journal
10502947 → ACNP
Volume
6102
Issue
2
Year of publication
2000
Database
ISI
SICI code
1050-2947(200002)6102:2<2119:NWIHNB>2.0.ZU;2-W
Abstract
Two approaches to extend Hardy's proof of nonlocality without inequalities to maximally entangled states of bipartite two-level systems are shown to f ail. On one hand, it is shown that the proof of Wu and co-workers [Phys. Re v. A 53, R1927 (1996)] uses an effective state which is not maximally entan gled. On the other hand, it is demonstrated that Hardy's proof cannot be ge neralized by the replacement of one of the four von Neumann measurements in volved in the original proof by a generalized measurement to unambiguously discriminate between nonorthogonal states.