The Study Of Spin Squeezing Properties In Interaction System Between Optical Field And Atom

Quantum entanglement is an important physical resource, which can be applied significantly in the quantum information processing and computation science. Spin squeezing and entanglement have a natural connection. Spin squeezing means the existence of entanglement in the system, at the same time means that we can get more high-precision measurements. In addition to spin squeezing coefficients can be used as entanglement criteria, in certain types of special state, it also has relatively simple relationship with concurrence.The quantum optics is a fast-developing subject. Many quantum optical systems have shown chaos phenomena. Since spin squeezing as a pure physical phenomenon is closely related to quantum entanglement, it is naturally for us to consider whether we can use it to character the quantum chaos in the physical systems.On the basis of introducing the research background, application and the relationship between quantum entanglement and spin squeezing, in this paper, the property of real and imaginary spin coherent state and the relationship between the mean spin direction (MSD) and spin squeezing are mainly studied by the definition of spin squeezing coefficients in Chap.4. In Chap.5, we systematically introduce the Dicke model, which describe the interaction of light and substance, and investigate dynamic nature of spin squeezing, and also expound the effect to spin squeezing in imaginary photon process. Then we analysis the numerical results.