A Bell Theorem Without Inequalities for Two Particles, Using Efficient Detectors

Abstract

We consider an entangled two-particle state that is produced from two independent down-conversion sources by the process of "entanglement-swapping", so that the particles have never met. We prove a Greenberger-Horne-Zeilinger (GHZ) type theorem, showing that the quantum mechanical perfect correlations for such a state are inconsistent with any deterministic, local, realistic theory. This theorem holds for individual events with no inequalities, for detectors of 100% efficiency.

15 pages, 2 embedded figures. This precedes and is a companion paper to quant-ph/0510207v2. There are only minor changes. This paper will appear in Phys. Rev. A