It can be said that quantum entangled states are involved in almost every part of quantum information and play an important role in quantum information . what are entangled states , which distinctive qualities do entangled states have and how to prepare entangled states 可以说今天量子信息的方方面面都涉及到纠缠态，纠缠态在量子信息理论中显示了极其重要的作用，这使得对量子纠缠态的研究具有十分重要的意义。
During my phd study , our group completed the experimental and theoretical investigations on cv quantum dense coding , generation of multipartite entangled state of optical modes and controlled dense coding quantum communication . following five parts will be presented in this thesis : 1 我们利用连续光场的正交分量量子纠缠特性，进行了连续变量量子密集编码，多组份纠缠态光场产生，受控密集编码量子通讯等实验与理论研究，主要内容如下： 1
For further use we state the holevo - schumacher - westmoreland theorem of the capacity of classical information tansmission when product states are used at the input and entangled measurements are used at the output , and the bennett - shor - smolin - thapliyal theorem of the capacity of classical information tansmission aided by entanglement between the sender and receiver 为后文应用，列出了在输入乘积态输出纠缠测量时的经典通信容量的holevo - schumacher - westmoreland定理，和发送者与接收者间有量子纠缠作为辅助时的经典通信容量的bennett - shor - smolin - thapliyal定理。
Subsequently discusses the philosophy " s problem which has been included in the development process of quantum " s entanglement , the theories of the quantum " s entanglement and application of the quantum ' s entanglement , points out the quantum ' s entanglement has great impact to society and world in the modern society 在随后的三个部分中分别对量子纠缠的发展过程、理论现状和应用情况中的哲学问题论述，揭示出量子纠缠理论在现代科技的发展下对社会和世界认识所带来的巨大冲击。
Utilizing entanglement , we can implement the disembodied transport of an unknown quantum state from one place to another remote place with high - fidelity , i . e . quantum teleportation . via entanglement , we can also improve the channel capacity of classical signal in quantum channel , i . e . quantum dense coding , even we can entangle two quantum systems that have never directly interacted with each other by means of entanglement swapping 利用量子纠缠，通讯双方可以实现对一个量子态的高保真度远程传输，即量子离物传态；利用量子纠缠，通讯双方可以实现经典信息的高信道容量传输，即量子密集编码；甚至可以使原本不纠缠的量子系统产生纠缠，即纠缠交换。
In this thesis , the preparation and measurement of bell states of two particles are introduced . a scheme for teleportation an arbitrary three - particle state is proposed , which is possible to extend for teleporting an arbitrary n - particle state . in terms of the basic logic gates , the quantum logic circuit for teleporting a qubit and an arbitrary two - particle state are also presented 本文从量子纠缠的非局域性的讨论出发，给出了两体纠缠的四个正交完备基及其测量方法，从未知量子态的隐形传送的基本原理出发，讨论了三粒子任意量子态的隐形传送过程，并讨论了推广到多粒子任意量子态的隐形传送的可能性。
Quantum information is an advanced research topic in modern science and technology . the fresh subject devotes to exploit the fundamental principle of quantum mechanics and the wonderful characteristic of quantum state , such as quantum entanglement , squeezing , superposition etc , to perform the processing , computation and transmission of information 量子信息是当今国际科学技术界的前沿研究课题，主要研究如何利用量子力学基本原理及量子态所特有的特性，如量子纠缠、压缩、态叠加等，完成信息处理、计算与传送。
In the last section , we show how entangled states are used in quantum dense coding , quantum cryptography and quantum teleportation . a new valuable scheme based on linear optical elements about teleportation of two - photon and multi - photon entangled states also has been proposed in this section . in this scheme t he probability of the successful teleportation is 50 % , which is optimal 量子纠缠在量子信息中的应用这一章中，我们将首先分别介绍量子纠缠在量子密集编码，量子密钥分布，量子隐形传态中的应用，然后提出一种利用线性光学方法实现纠缠态的隐形传送方案，此方案的成功率为50 ，这也是目前为止最佳的成功几率。
Quantum information science is a new subject combining quantum theory and information science . great progress has been made in quantum teleportation , description of quantum entanglement and classification of quantum states . according to this , the following work has been completed : ( 1 ) a scheme for teleporting an unknown n - dimensionni - particle state by making use of the maximum entangled state as quantum channel is proposed 量子信息学是量子力学理论和计算机理论相结合而产生的一门新的交叉学科，在量子隐形传态、量子纠缠态的描述及量子态的分类等领域取得了重要进展，本文围绕这几个方面开展了如下研究工作： ( 1 )在文章的第二章研究了多能级多粒子量子态的传输。
This dissertation is organized as follows . in chapter one , firstly we review the development of quantum optics , pointing out three features of quantum optics : coherence , nonlinearity , and quantity , next something of quantum entanglement is discussed , including the conception of entangled state and definition of the degree of the entanglement , at last , the j - c model of the interaction between the atoms and the optical fields . in chapter two , we introduce the concepts and properties of coherent state and shrodinger - cat state 本文首先回顾了量子光学的发展历史，着重指出了量子光学的三个显著特征，即相干性、非线性和量子性，然后讨论了量子纠缠方面的内容，包括纠缠态的概念及其度量? ?纠缠度等，最后阐述了原子与光场相互作用的理论模型j - c模型；第二章介绍了相干态和猫态的概念及性质；第三章的内容是两纠缠原子与光场相互作用过程中光场的压缩效应。
