Device-independent (DI) protocols, such as DI conference key agreement (DICKA) and randomness expansion (DIRE), certify private by observing nonlocal correlations when two or more parties test a Bell inequality. While most protocols are restricted to bipartite tests, harnessing multipartite may lead better performance. Here, we consider tripartite DICKA DIRE based on testing inequalities, speci...

In a controversial paper recently published in this journal, Marian Kupczynski claims that Bell-CHSH inequalities cannot be derived for classical probabilistic causal model of typical Bell experiment. Such an experiment can seen as built up four separate components, one each the different combinations settings used "Comment" we show his claim is false and logical reasoning incorrect.

Quantum mechanics and relativistic causality together imply nonlocality: nonlo-cal correlations (that violate the CHSH inequality) and nonlocal equations of motion (the Aharonov-Bohm effect). Can we invert the logical order? We consider a conjecture that nonlocality and relativistic causality together imply quantum mechanics. We show that correlations preserving relativistic causality can viola...

WARNING This is a revised version with respect to the one submitted on Mon, 3 Jul 2000. By mistake an earlier version and not the final one was submitted. Abstract We prove that the locality condition is irrelevant to Bell in equality. We check that the real origin of the Bell’s inequality is the assumption of applicability of classical (Kolmogorovian) probability theory to quantum mechanics. W...

Bell proved in 1965 [ 1 ] that nonlocality is an unavoidable property of quantum theory. By assuming locality, he derived a set of inequalities which, he then showed. are violated by the predictions of quantum theory. Since then a number of different Bell inequalities have been discovered, the most important of these are the Clauser, Horne, Shimony, and Holt (CHSH ) inequalities [ 21 derived in...

We investigate the scenario where an observer, Alice, shares a two-qubit state with arbitrary number of observers, Bobs, via sequentially and independently recycling qubit in possession first Bob. It is known that there exist entangled states which can be used to have arbitrarily long sequence Bobs who violate Clauser-Horne-Shimony-Holt (CHSH) Bell inequality single Alice. show do not whose ent...

The development and wide application of quantum technologies highly depend on the capacity communication channels distributing entanglement. Space-division multiplexing (SDM) enhanced channel capacities in classical telecommunication bears potential to transfer idea using current infrastructure. Here, we demonstrate an SDM polarization-entangled photons over a 411m long 19-core multicore fiber ...