Quantum Correlations Dynamics Of Quantum Systems In Classical Noisy Environments

In recent years, people have vigorously investigated the quantum correlations dynamics of open quantum systems in the quantum noisy environments, and have obtained a number of important research results. However, most of the discus-sions are limited to the effect quantum noisy on the quantum correlation dynam-ics, and less researches involved in the classical noisy environment, especially less researches are involved in the quantum correlations of multipartite systems in the classical noisy environments. Hence, researching the influence of classical noisy en-vironment on the quantum correlations dynamics of quantum systems in quantum information processing and computation has an important theoretical significance and application value. This thesis is mainly focused on the quantum correlations dynamics of open quantum systems in the classical noisy environments, some in-novative results are obtained. This thesis falls into six chapters, in which chapter two to five constitute the major part of my work. The main contents are as follows:In Chapter 1, a brief introduction to the research back ground and the general situation of quantum correlations are firstly given, and then review the general con-cepts of quantum entanglement and quantum discord, as well as its quantification. Finally, the basic theory of open quantum systems is briefly introduced. In Chapter 2, the degree of non-Markovian behavior for a qubit system driven by a classical phase noisy laser (CPNL) is investigated. We analyze the dynamics of the rate of change of the trace distance in two different dynamical regimes in relation to the values of the system parameters. The results show that, the behavior of the non-Markovianity depends on the ratio of the CPNL rate and the system-environment coupling strength. In the non-Markovian classical noise region, the non-Markovian character becomes less evident when the ratio of the CPNL rate and the system-environment coupling increases.In Chapter 3, the dynamics and protection of quantum discord for two un-coupled qubits driven by classical phase noisy laser(CPNL) are investigated. We in detail investigate the dynamics of quantum discord in both Markovian classi-cal noise and non-Markovian classical noise regimes. The results show that, the dynamics of quantum discord depends on the ratio of CPNL rate and the system-environment coupling strength. The quantum discord can be well protected by increasing the ratio in the Markovian classical noise region or by decreasing this ratio in the non-Markovian classical noise region. Besides, we explain the revivals of the quantum discord by means of the increase of parameter used to quantify non-Markovianty of the single qubit dynamics in the non-Markovian classical noise region.In Chapter 4, we exploit the notions of tripartite quantum discord D(3),tripar-tite negativity N(3) and entanglement witnesses (EWs) as a measure of quantum correlations in a model of three noninteracting qubits subjected to a classical ran-dom external field, respectively. Comparing the dynamics of D(3) with that of entanglement for the initial entangled pure or mixed GHZ- and W-type states, it is found that the quantum correlations dynamics depend on the input configura-tion of the initial states purity. The results show that, D(3) may be more robust than entanglement, and no sudden death of the D(3) occurs while entanglement displays periodically sudden death and revivals in the regions for GHZ-and W-type states driven by classical random external field. Furthermore, the survival partial entanglement can be detected by means of the suitable EWs.In Chapter 5, the phenomena of the sudden death of distillability (DSD) for a two-qutrit anisotropic Heisenberg chain with Dzyaloshinskii-Moriya (DM) interac-tion in an inhomogeneous magnetic field are studied. By using of the realignment criterion and negativity, it is shown that certain initial prepared free entangled states may become bound entangled or separable states in a finite time. More-over, the influences of the isotropic bilinear interaction parameter, the external magnetic field strength, the DM interaction parameter, as well as the intrinsic de- coherence parameter on the possibility of DSD have been in detail discussed. The results show, controlling the isotropic bilinear interaction parameter, the exter-nal magnetic field strength, the DM interaction parameter, as well as the intrinsic decoherence parameter, can accelerate the possibility of DSD in the present model.In Chapter 6, A summary and outlook are presented.