The Quantum Entanglement Of Two Two-level Atoms System

Quantum entanglement is the most inconceivable characteristic of quantum mechanics different from the classical physics.The quantum entanglement state has the special physical property so that the quantum infbrmation has many new characteristics different from the classical information:and the quantum entanglement state has also been viewed as a new physical resource of quantum information transmission and quantum information processing.Research on the quantum entanglement state and its application in the quantum information science has importantly significant and valuable.The quantum entanglement of two two-level atoms is mainly studied in this article.The whole thesis consists of four chapters.In chapterâ… ,the basic theory of quantum entanglement is presented. Firstly,the definition and properties of the quantum entangled states are introduced. The several kinds of quantum entangled states are given.Secondly, the measurement of the degree of quantum entanglement and manipulation of quantum entanglement are discussed.Finally,the main content of the article is briefly provided.In chapterâ…¡.the quantum entanglement of two partially entangled twolevel atoms interacting with a single mode vacuum field is investigated.The quantum entanglement between two partially entangled two-level atoms and the vacuum field is explored by using the quantum reduced entropy,and one between two two-level atoms is studied by using the quantum relative entropy. The influences of the atomic dipole-dipole interaction intensity on the quantum entanglement of the system are also discussed.The results show that:the system exhibits periodic quantum entanglement dynamics,and the magnitude and the period of quantum entanglement depends on the atomic dipole-dipole interaction.The atom-field maximal quantum entanglement state and atomatom maximal entanglement state can be prepared by selecting appropriate system parameters and the interaction time.In chapterâ…¢,the quantum entanglement of two two-level atoms simul- taneously interacting with a single-mode cavity field and droven by a strong classical field is investigated.The results show that With the large detuning and the strong driving,field,the quantum entanglement between two two-level atoms which,are initially prepared in the ground states is generated.The atomic system exhibits periodic quantum entanglement dynamics,and the period of quantum entanglement only depends on the single-mode cavity field. With the large detuning and the strong driving field,the quantum entanglement degree between two two-level atoms which are initially prepared in the maximal entanglement states is maintained well.The different maximal quantum entanglement state of the atom-atom can be prepared by selecting appropriate system parameters and the interaction time.In chapterâ…£,the summarization and the hope are presented.