A Study Of Nonlocality In Quantum Correlation

In 1935,Einstein,Podolsky and Roson et al.published a paper called "EPR paradox",which triggered a heated discussion and extensive research on quantum entanglement among physicists for decades and even today.Since it began to develop a series of basic properties belonging to the quantum world--quantum correlation,has been the basis and focus of the quantum information discipline,including Bell nonlocality and EPR steering.With the rapid development of quantum information,people begin to realize that the study of quantum correlation and non-locality theory can better improve the theoretical framework of quantum mechanics,and promote the development and growth of quantum computing and quantum communication,so as to realize the arrival of the era of quantum hegemony.The main research object of this thesis is Bell nonlocality and EPR steering in quantum correlation.In this paper,we discuss how to detect the two kinds of quantum correlations respectively,starting from the all-versusnothing form of detection.In terms of Bell nonlocality,this paper mainly extends the theory of Hardy paradox,discusses the form of Hardy paradox in the case of multibody Bell nonlocality,and summarizes all the existing Hardy paradoxes according to hierarchy of multipartite nonlocality.In the study of EPR steering,this paper mainly extends the all-versus-nothing detection method to the way of maximum value,and compares it with the original way,as well as the relevant discussion on its experiment.Finally,we focus on the research of Bell's nonlocality on quantum network.According to the Bell inequality of quantum network nonlocality given in relevant literature,we verify the nonlocality and independent dimensions of different networks,especially the discussion on the nonlocality model of quantum network with graph state,and put forward a lemma and theorem.It is shown that the quantum networks discussed in this paper have similar conclusions to those in the literature.That is,the quantum network of equivalent model composed by arbitrary intents states is k-nonlocal.