EPR Steering Criteria And The Relation Between Quantum Steering And Nonlocality

As the core of quantum information theory,quantum entanglement and nonlo-cality challenge human's intuition and understanding about nature,which also become emerging resources in today's quantum information technology.As a subtle supplement to entanglement and Bell nonlocality,EPR steering stands as a bridge between the two concepts.From a theoretical point of view,EPR steering is a sufficient condition for entanglement,and a necessary condition for nonlocality.From a practical point of view,EPR steering helps to construct novel communication protocols in specific scenarios.This dissertation has reviewed results of the author's study and research on EPR steering during his PhD program.After an introduction of basic quantum information theory and history of EPR steering,criteria of EPR steering and its relationship with other physical concepts,like the nonlocality,are studied in detail.In the EPR steering criteria's part,a linear criterion and a local-uncertainty-relation based criterion are developed.Both criteria are constructed in an experimental-friendly manner.Precisely,by reducing overheads of computational resources demanded in pre-vious criteria,the current ones can be directly applied in real experiments with arbitrary settings and arbitrary outcomes.Moreover,an analytical method for the optimization of EPR steering detection is also systematically maintained.Furthermore,we have pro-vided some physical insights that,local uncertainty relations actually play an important role in the correlation exhibited by bipartite systems.In the relation between quantum steering and nonlocality's part,the dissertation has mainly focused on the role of quantum steering in the maximal violation of Bell inequal-ities.Many classes of Bell inequalities have been verified that,when they are maximally violated,Alice's optimal measurements always steer Bob's local state to certain states,such that the observation values of respective effective operators are maximized.How-ever,this property does not holds for all equivalent Bell expressions under no-signaling constraints.It implies that there is a special Bell expression so as to make this property valid.Our results therefore supplement the current study of nonlocality,and offer a novel method for the investigation of quantum correlation and quantum foundation.