| Quantum correlation is a fantastic physical property in the microcosmic quantum world. It has brought us many new marvelous insights into the quantum physics and computer sci-ence. Quantum entanglement is a kind of quantum correlation, which has been payed much attention to study. It can be an important physical resource used in quantum information science. It is essential for certain kinds of quantum information tasks like quantum telepor-tation, quantum cryptography and quantum computation. Recently, new studies show that a more general quantum correlation, quantum discord, can play a critically important role in quantum process information. The main emphasis of our research is the quality of quantum discord and entanglement effected by subsystem’s interaction, DM interaction and quantum feedback control. This thesis is arranged as follows:1、Quantum discord and entanglement of a bipartite composite system in the presence of a dissipative environment and effect of the interaction between the two subsystems were studied. The sudden transition between classical correlation and quantum correlation for the maximally mixed marginals initial states has also been considered.2、Compared quantum discord to entanglement in the bipartite Heisenberg model with the Dzyaloshinskii-Moriya (DM) interaction of thermal equilibrium state. The effects of the DM interaction on the quantum discord were discussed in detailed.3、Dynamics of quantum correlation for an open bipartite system under quantum feed-back control were considered. Different types of quantum correlations have been investigated and compared with the state of initial maximally mixed marginals as well as steady situation.The thesis has been divided into five parts, and our works are included in the chapters from1to3. The results are summarized in the end. |
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