光子纠缠

并讨论了光子纠缠在量子通信中的两个方面的应用：量子远程传态和量子密集编码。

This dissertation discusses two applications of photon entanglement in quantum communication : quantum teleportation and quantum dense coding .

理论计算表明：在量子成像架构下，当使用N光子纠缠源时，成像的空间分辨率比起经典光学提高N倍。

Theoretical calculation showed that in the framework of quantum imaging , the spatial resolution of imaging could be N-times of classical optical when using N-photon entangled resource .

主要研究成果如下：1.实现了六光子纠缠GHZ态和簇态的制备。

The main results are listed as follows : 1 . We have realized the preparation of the six-photon GHZ state and cluster state .

第二章介绍了在腔QED系统中制备原子-光子纠缠态的方法，提出了利用腔QED技术制备多原子-原子纠缠态的方案。

In chapter 2 , the methods of preparation of atom-photon entangled states in cavity QED are expatiated and the scheme of multi-atom entangled state preparation is proposed by using cavity QED technique .

光子纠缠态制备、应用及演化的实验研究

The Experimental Research on the Preparation , Application and Evolution of Entangled-photon States

量子信息技术的新进展&五光子纠缠和开放目的的量子隐形传态

Experimental Demonstration of Five-photon Entanglement and Open-destination Teleportation

增加光子纠缠相干态的统计性质

Statistical properties of photon-added entangled coherent state

本文提出一种利用叠加态的输入光来产生宏观原子&光子纠缠对的方案。

We propose a feasible scheme to create macroscopically entangled atom-photon pairs by preparing an input optical superposition state .

在高精度测量和量子信息科学中，制备和操纵原子&光子纠缠对具有重要作用。

The making and manipulation of entangled atom-photon pairs are useful for , e.g. , high-precision interferometry and quantum information science .

叙述了自发参量下转换制备双光子纠缠态技术的发展历程、技术原理以及在量子信息学中的应用，并介绍了国内这一领域的进展。

The development of preparing two-photon entangled state by spontaneous parametric down-conversion , its principle and use in quantum information are described , and the domestic progress in this fieldis introduced .

通讯双方使用的量子信道是两个单光子纠缠态.通过使用分束器作用和对输出态进行光子测量以及在经典信息的帮助下，纠缠转移和量子隐形传态的过程被完成。

The process of the entanglement translation and quantum teleportation are achieved by using the 50 / 50 symmetric beam splitters and the photon detectors with the help of classical information .

利用晶体的非线性性质，通过自发参量下转换产生光子纠缠对具有产生效率高、容易操纵等优点，在量子操控技术的发展中具有巨大的应用前景。

By virtue of the characteristic of nonlinear optical crystal , the entangled state produced in this way has high entanglement degree and high fidelity , besides , it is easy to control .

在实验上发展了多光子纠缠技术，利用已有的四光子纠缠技术结合新发展的单光子源技术，在世界上第一次实现了五光子纠缠。

Based on the technique developed in previous multi-photon interferometry , we experimentally combine an entangled four-photon state with a single photon state to achieve the first ever entanglement of five photons in the world .

其中我们介绍了远程制备任意两粒子纠缠态的方案，同时在制备光子纠缠态的过程用到了一些线性光学元件，交叉克尔非线性和零拍探测，所以首先介绍-些线性光学元件。

And we introduce the scheme of remote preparation of an arbitrary two-particle state . In the process of preparation of photon entangled states some simple linear optical elements , cross-Kerr nonlinearity and homodyne measurement are introduced .

本文主要讨论线性光学在量子信息技术中的应用。内容包括光子纠缠的产生，光量子信息技术中常用的操纵和测量技术。

This dissertation discusses the quantum information fundamentals and its realization by linear optics approach , the content of which covers the technique of generating entangled photons by spontaneous parametric down-conversion process , as well as method of manipulation and measurement of single photon .

首先回顾Sun等人的研究工作，关于原子光子间纠缠的生成及其分布，其中突出强调经典外场驱动对QED腔中原子光子间产生纠缠的影响。

In the first section we introduce the research results of Sun et al which studied the atom-photon entanglement preparation and distribution , and analyzed the role of the classical external field on atom-photon entanglement in cavity QED system .

通过计算光子加纠缠相干态的光子数分布、Cauchy-Schwartz不等式、二阶关联函数，研究了光子加纠缠相干态的非经典性质。

The properties of the photon-added entangled coherent states are studied by calculating Cauchy-Schwartz inequation , photon-number distribution and second-order correlation function .

基于单光子模式纠缠态提出了量子辅助克隆方案。

We proposed a scheme for quantum assisted cloning based on single-photon entangled states .

另一方面，利用量子点发出的单光子或纠缠光子对，可以用来传输单个比特的量子信息。

On the other hand , the emitted single photon and entangled photon pairs can be tools for quantum communications .

基于双光子超纠缠态提出了将其作为量子信道用于量子安全直接通信的两种方案，为实现更安全、更高效的量子保密通信提供了理论基础。

We proposed two protocols about quantum secure direct communication based on three-dimensional hyper-entangled states , which provided as the theoretical basis for the realization of a more efficient and safer quantum cryptography communication .

一度认为，只有基于纠缠态双光子的纠缠光源，才能实现鬼成像；但近年来的研究表明，经典热光场也能实现这一过程。

For a time , entanglement was thought to be a prerequisite , while we know now that classical thermal light can imitate this kind of imaging and there is no need for entangled beams .

多重准相位匹配过程可以有效减少外部分立光学元件，使得光子偏振纠缠的产生变得高效、易于收集、集成、稳定、便携。

Such photonic polarization entangled states have many advantages such as high efficiency , easy to collect , integrated , stable and portable since multiple QPM processes can effectively reduce the external discrete optical elements . 2 .

基于光学超晶格材料，利用多重准相位匹配技术是制备双光子超纠缠态的有效途径。4.将光学超晶格产生的新型纠缠态应用于量子信息领域。

It is a very effective method for integrated engineering of hyper-entanglement with QPM technique based on OSL . 4 . We adopt the new types of entangled photon sources generated from OSLs to be applied in the fields of quantum information .

QKD系统的光源主要有单光子光源和纠缠光源两种。

Single photon sources and entangled photon sources are the main light sources of QKD systems .

当前，尽管人们基于腔QED系统已成功制备了原子-原子纠缠、光子-原子纠缠等，但在多原子体系中，对每个原子和光子的量子态独立操控仍是当前实验技术的一个难点。

Up to now , the generation of atom-atom entanglement , photon-atom entanglement is realizable based on cavity QED . However , the individual control of single atoms in multi-atoms systems is still very difficult with current technologies .

第二章主要讨论通过腔量子电动力学（QED）制备纠缠态：首先研究远程制备光子-光子纠缠态，然后提出了使用纠缠交换产生和浓缩多原子纠缠态的方案。

In chapter ⅱ, we study on the ways of preparing quantum-entangled states in cavity QED , including practical scheme for remote state preparation of a photon-photon entangled state , and generation and concentration of multi-atom entangled states .

有趣的是，系统最终将处于稳定的纠缠态，这就实现了从借助噪声使原子间产生纠缠到使原子&光子间产生纠缠的推广。

It is of interest that the systems of atom - photon eventually evolved into a steady state .

利用卫星来分发单光子（或纠缠光子对）的方法为远程量子通信网络提供了一种独特的解决方案。

Using satellites to deliver single photon or entangled photon pairs is a unique solution to realize long-distance quantum communications networks .

存在于不同自由度之间或不同光子之间的纠缠会引起自由度或光子的可区分性，并会导致实际实验中的干涉可见度下降。

It shows that the entanglement may exist between different photons and different degrees of freedom . These entanglement will drop the visibility in practical photonic interference .

量子身份认证方案主要基于单光子测量和纠缠态测量。

Quantum identity authentication schemes are mostly based on single-photon state measurement and entangled state measurement . A quantum identity authentication and key distribution scheme based on quantum one-way function is proposed .