量子信息学是一门关于数学、物理、计算机、信息学的交叉学科。量子纠缠作为一种基本的物理资源，是量子信息的核心，在量子信息处理的众多研究领域中起着重要作用。在以光子作为量子比特的物理系统中，借助于cross-Kerr非线性来实现光子之间的相互作用，使光子产生纠缠，从而实现量子信息处理的研究引起了广泛关注。一方面，有效地产生、测量量子纠缠态是量子信息处理领域中的一个重要任务。另一方面，量子逻辑门是实现量子计算的基本单元，尤其是单量子位逻辑门和两量子位逻辑门是构造量子计算机的通用门。本项目主要探讨利用cross-Kerr非线性进行量子纠缠态的产生、测量及两量子位逻辑门的构造，并分析消相干环境对这些过程的影响。进而将其应用于具体的量子通信过程，设计最优的量子隐形传态、量子密集编码、量子克隆等量子通信方案，为实验上实现提供一些具体的量子线路。

Quantum information science is an interdisciplinary subject which involves mathematics, physics, computer, and informatics. Quantum entanglement, as a powerful physical resource, is on the core of quantum information and bacomes an appealing issue due to its enchanting merits. Optical quantum information processing has been investigated quite extensively and deeply, in which, the interaction between the photons is induced by using a cross-Kerr nonlinear medium and makes the photons be entangled. On the one hand, the generation and measurement of quantum entangled states are the important research issues in the filed of quantum information processing . On the other hand, quantum logic gates is a fundamental element of quantum computation. It has been shown that a quantum computation network can be decomposed into a series of logic gates, and the one-qubit and two-qubit logic gates are universal for constructing a quantum computer. We will study the generation, analyzation of quantum entangled states and implementation of two-qubit logic gates with cross-Kerr nonlinearity, as well as analyzing the decoherence such as photon loss, phase noise effects on the process. Moreover, we will also discuss how to apply it to the concrete quantum communication, to find optimal quantum teleportation, quantum dense coding and quantum cloning protocols, and to implement feasible quantum network for these process in experminent.