On Quantum Nonlocality and the Device-independent Paradigm

Abstract

Nonlocality is one of the most fascinating aspects of quantum theory. It is a concept that refers to stronger-than-classical correlations between the components of space-like separated systems, and a clear manifestation of entanglement, although these two concepts are not trivially related. With the recent advent of quantum information theory, nonlocality has gained the status of resource: it can be used to securely evaluate particular tasks without relying on assumptions about the devices that are supposed to implement such protocols - a device-independent assessment. The thesis is focused on the study of nonlocality theory and its applications to device-independent assessment of quantum phenomena. Special emphasis is given to a protocol for device-independent assessment of measurement devices and to a device-independent formulation of Hardy?s test of nonlocality. Also, on more fundamental grounds, recent developments on the relation between entanglement and nonlocality are presented, regard- ing, specially, the idea of activation of nonlocality on multipartite quantum networks.