The Study Of Quantum Correlation And Coherence In Open System

Quantum properties in quantum systems are important physical resources and widely used in quantum information processing task. Hence, it is the basic task to study quantum properties in quantum information. However, due to the existence of the surrounding environ-ment, the system is inevitably disturbed and the quantum information during transmission is largely destroyed. For example, quantum decoherence, quantum infidelity, quantum dis-entanglement can happen. Therefore, it is our main goal to make it clear that how the environment affects our system of interests. The master equation is our usual method to study the open quantum system, quantum system considering the environment. According to whether to consider the information backflow in the environment, the master equation includes the Markovian and Non-Markovian master equations. In the article, we mainly consider the Markovian master equation.In this paper, we focus on the quantum features such as quantum fidelity, quantum con-currence, quantum correlation, quantum coherence in the open quantum system. This paper includes four chapters in detail. In Chapter 1, we briefly introduce quantum mechanics and quantum information theory and present the outline of the thesis. In Chapter 2, we start to introduce the basic knowledge of quantum information, including the basic concepts of qubit, the density matrix and some important physical quantities:quantum entanglement, quantum correlation, quantum coherence, fidelity and quantum channel. In Chapter 3, we study the roles of a quantum channel on a quantum state by using the infidelity and decoherence as a measure, and give our results. In Chapter 4, we first introduce the open quantum systems and give the derivation of the master equation, and then study the interaction between the two-qubit system and the non-equilibrium squeezed reservoir. We find out how the squeeze parameters affect quantum coherence, quantum entanglement, local quantum uncertainty and the heat current. Finally, the conclusion and the discussion are drawn.