Macroscopically local correlations can violate information causality.
Although quantum mechanics is a very successful theory, its foundations are still a subject of intense debate. One of the main problems is that quantum mechanics is based on abstract mathematical axioms, rather than on physical principles. Quantum information theory has recently provided new ideas from which one could obtain physical axioms constraining the resulting statistics one can obtain in experiments. Information causality (IC) and macroscopic locality (ML) are two principles recently proposed to solve this problem. However, none of them were proven to define the set of correlations one can observe. In this study, we show an extension of IC and study its consequences. It is shown that the two above-mentioned principles are inequivalent: if the correlations allowed by nature were the ones satisfying ML, IC would be violated. This gives more confidence in IC as a physical principle, defining the possible correlation allowed by nature.
Centre for Quantum Technologies, National University of Singapore, Block S15, 2 Science Drive 3, 117542, Singapore. dcavalcanti@gmail.com
Daniel
D
Cavalcanti
Alejo
A
Salles
Valerio
V
Scarani
Phys Rev Lett. 2007 Nov 2;99(18):180502
17995388
Nature. 2009 Oct 22;461(7267):1101-4
19847260
Phys Rev Lett. 2007 Jan 5;98(1):010401
17358458
Phys Rev Lett. 2006 Jun 30;96(25):250401
16907289
Science. 2010 Nov 19;330(6007):1072-4
21097930