Quantum nonlocality, i.e. the fact that distant observers performing local measurements on a shared entangled quantum state can violate a Bell inequality, is a key feature of quantum theory. Of particular interest is the investigation of quantum nonlocality in the context of general networks: Here, a set of distant observers share entanglement distributed by several sources which are assumed to be independent from each other.

In my talk, I focus on the case of the triangle network, were three parties share three sources, each party being connected to a different pair of sources. I introduce the Finner inequality and show that it holds in the case of quantum models and for wiring of nonlocal boxes. I discuss its interpretation in terms of resource theory.

Finally, I show that despite this inequality holds either when the source are “classical” or “quantum”, it can be exploited to find what is maybe the first “genuine“ example of quantum correlation which cannot be obtained with “classical” sources in the triangle network.


Seminar, October 10, 2018, 15:00. ICFO’s Blue Lecture Room

Hosted by Prof. Antonio Acín