Entanglement Dynamics In The Double Jaynes-Cummings Models

Quantum entanglement is the fundamental resources of quantum computation and quantum information processes. producing, maintaining and manipulating the quantum entanglement state is the key problem of preparing engineering of quan-tum entanglement. In this paper, using the basic theory of quantum entanglement and J-C model, the entanglement dynamics of the atoms in the double J-C models with the Kerr medium, the double intensity-dependent coupling J-C models and the double J-C models which containing two atoms with the dissipation of two cavities are investigated respectively, some innovative results are obtained and the main contents of this paper are as follow:In chapter 1, some basic theories of quantum entanglement are introduced, including the measurement of entanglement and its application.In chapter 2, some basic theories of J-C model are exposited. First of all, the derivation of the Hamiltonian of the standard J-C model. The basic dynamics of the J-C model with Kerr medium and the intensity-dependent coupling J-C model are provided; then the basic theory and the properties of the double J-C model are introduced; Finally, the work have been done in this paper are introduced.In chapter 3, the double Jaynes-Cummings models with the Kerr medium is extended from the Jaynes-Cummings models with the Kerr medium, the entan-glement dynamics of this model is presented. The effect of the Kerr medium on that is examined. The result shows that, the Kerr medium can control the en-tanglement dynamics of the atoms and repress entanglement sudden death. The maximum entanglement between the atoms is obtained by strengthening the non- linear interaction of the Kerr medium.In chapter 4, the double intensity-dependent coupling J-C model is extended from the intensity-dependent coupling J-C model?And the entanglement dy-namics of the double intensity-dependent coupling Jaynes-Cummings models is presented with two different initial light field, which one is in the squeezed vac-uum state and another is in the coherent state. The result shows that, when the compressibility factor and the mean photon number are smaller, the concurrence of atoms exhibits phenomenon of dead and revival periodically, and as the value of them grow larger, the entanglement sudden death come out. It is found that it is possible for the entanglement to be perfectly transferred between the atoms and the fields. Using this result, the periodic pulse of entanglement can be prepared, and it may be useful for quantum information processing.In chapter 5, the dynamics of atomic entanglement in double Jaynes-Cummings models containing two-level atoms or A-type three-level atoms with the dissipation of two cavities are investigated respectively. The influences of the damping con-stant k and the mean photon number|?|of the fields, and the relative difference of the atomic couplings (the relative difference of the Stark shift parameter) on the entanglement between the two two-level atoms (the two A-type three-level atoms) are examined.The result shows that, no matter the atoms is two-level atoms or A-type three-level, the entanglement between the two atoms decay to a steady value after a period of time of oscillations, and the rate of decaying depend on the value of k/g and |?|. The steady entanglement between the two atoms will be stronger when the damping constant k is larger, and will be weaker when the field intensity is bigger. And the entanglement decreases most slowly for (?)?1.In chapter 6, the summarization and the hope are presented.