1209.0112 (Adan Cabello)

Twin inequality for fully contextual quantum correlations    [PDF]

Adan Cabello

We identify a simple tight noncontextuality inequality involving yes-no tests whose maximum quantum violation reaches the upper bound imposed by the laws of probability. In a sense, this is the simplest tool for testing quantum correlations with zero noncontextual content (i.e., fully contextual quantum correlations) and presents an intriguing similarity with the Klyachko-Can-Binicioglu-Shumovsky inequality [Phys. Rev. Lett. 101, 020403 (2008)], the simplest inequality violated (without reaching the probabilistic bound) by quantum systems of dimension three. We prove that the quantum violation of the twin inequality requires quantum systems of dimension six.

View original: http://arxiv.org/abs/1209.0112