Optimized Detection Of Maximally Entangled Time-bin Qutrits

Starting from the EPR paradox,this essay introduces the conflicts between quantum mechanics and classical physics theories.Based on the core ideas in the EPR paradox,the mathematical representation of the local hidden variable model based on the Bell scenario is introduced;the geometric meaning and specific construction method of the local hidden variable model are explained;the relationship between the local hidden variable model and the nonlocality are discussed.the mathematical form of Bell's inequality(such as CHSH inequality)and its physical meaning are further introduced.Secondly,based on the basic assumptions of quantum mechanics,this essay explains the connection between quantum mechanics and Bell's inequality,discusses the violation of Bell's inequality in quantum mechanics,and further elaborates the connection between local realism and quantum mechanics,and Emphasizes the importance of quantum entanglement in quantum mechanics.In this essay,based on the special properties of quantum entanglement and its important role in the field of quantum communication,on the basis of introducing the mathematical representation and physical meaning of quantum entanglement,several schemes of entanglement detection are discussed.This essay focuses on entanglement witness,a method widely used in the field of entanglement detection,and elaborates its construction method and its specific implementation in the experiment.Based on the basic principles of quantum optics and the mature technical means of optical fiber communication,and relying on the above theoretical foundation,this essay implements the operator optimization and experimental measurement for the quantum entanglement witness operator.The main innovations of this essay are:1.an entanglement witness experiment using the fidelity-based entanglement witness operator was implemented.the entanglement dimension detection scheme based on the hypothesis testing idea in statistics and the SDP optimization algorithm is used to detect the entanglement dimension of the quantum state.Based on the target quantum state generated in the experiment,this essay designs a comparative experiment on traditional entanglement witness and entanglement dimension detection.2.Using the time-bin entanglement method to prepare the entangled state to be measured.using the unique principle of Mach-Zehnder interferometer to build the experimental optical path.And designing the projection measurement combination required for the experiment,and complete the complete measurement of the two sets of experiments.Through the analysis of the experimental results in this essay,it is found that the optimized entanglement witness measurement is more accurate,the restrictions on the experimental conditions are significantly reduced,and the number of combinations of entanglement witness operators is significantly reduced.Especially in the case of excessive noise interference during the experiment,the optimized detection of the entangled state still has good experimental repeatability,which is a feature that the traditional entanglement witness measurement does not have.Therefore,the optimized entanglement witness measurement provides a new and more stable method and idea for the entanglement witness experiment of higher-dimensional entangled states.