Thursday, October 11, 2012

1210.3018 (T. Fritz et al.)

Local orthogonality: a multipartite principle for correlations    [PDF]

T. Fritz, A. B. Sainz, R. Augusiak, J. B. Brask, R. Chaves, A. Leverrier, A. Acín
In recent years, the use of information principles to understand quantum correlations has been very successful. Unfortunately, the programme is limited by the fact that all principles considered so far have a bipartite formulation, but intrinsically multipartite principles, yet to be discovered, are known to be necessary for reproducing quantum correlations. In this work, we introduce an intrinsically multipartite principle which states that events involving different outcomes of the same local measurement must be exclusive, or orthogonal. We call this principle Local Orthogonality. We prove that the principle is equivalent to no-signaling in the bipartite scenario but more restrictive for more than two parties, and that despite the equivalence, some bipartite supra-quantum correlations can be shown to violate Local Orthogonality when distributed among several parties. Finally, we show how its multipartite character allows revealing the non-quantumness of correlations for which any bipartite principle fails. We believe that local orthogonality is a crucial ingredient for understanding no-signaling and quantum correlations.
View original: http://arxiv.org/abs/1210.3018

No comments:

Post a Comment