基于量子点的分布式量子计算.pdf

温州大学硕士学位论文 i 基于量子点的分布式量子计算 摘 要 信息科学的不断发展不仅改善了人类生活的质量而且推进了社会文明进步，随着世界范围内信息量的增长速度越来越快，传统计算机性能的提高远远满足不了人类社会信息量的增长所提出的需求； 同时在不久的将来，晶体管体积将会缩小到原子级别从而出现量子效应， 这就引起了是否能设计一台新的建立在量子物理规律基础上的量子计算机，因为它不但能解决经典计算机不能解决的问题,而且量子计算机又具有响应速度快、能量消耗低、储存量大和并行计算能力强等特点 量子计算机物理实现的方案有很多， 本文研究了量子点的物理实现方案，量子点方案可以直接利用现有的大规模集成电路技术，基于固态材料和固态电子技术,更适合集成化和小型化，且制造和控制都有强大的基础,所以在量子计算机的物理实现方面有着一致看好的前景然而量子点之间的相互作用很弱，为了加强远距离的量子点之间的相互作用且减少量子点系统的消相干， 采用了把量子点放在腔中的方法基于这个模型并且围绕着量子点的分布式量子计算的实现，本文首先介绍量子计算的基本概念和量子计算的物理实现方案， 然后从温州大学硕士学位论文 ii 量子态的制备、量子门的实现、量子测量的完成和量子信息的传输等方面具体介绍了量子点方案的实现情况。

重点介绍了我的研究工作： 1.量子点方案中纠缠态的制备在腔－量子点系统中，使单光子连续通过腔，从而产生量子点纠缠态 2.量子点系统中可控的量子隐形传态在腔中利用法拉第旋转，首先产生单光子和量子点的电子自旋的纠缠态， 然后完成可控的量子隐形传态，最后采用单光子测量的方法完成量子点自旋态的测量，使传态的成功几率为 1，可以增加网络的安全性 3.量子点纠缠态的隐形传态的实现 同样在腔－量子点中利用单光子完成量子点纠缠态的隐形传态， 也采用单光子测量的方法完成量子点自旋态的测量，这对分布式量子计算的实现有很大的意义，还可以扩展量子计算网络 关键词：分布式量子计算，量子点，纠缠态，量子隐形传态 温州大学硕士学位论文 iii DISTRIBUTED QUANTUM COMPUTATION BASED ON QUANTUM DOTS ABSTRACT The development of Information science improves not only the quality of life but also the progress of social civilization. The amount of information develops quickly in the whole world, the capability of classical computation can not satisfy the need of human society. At the same time, the volume of transistor reduces to the level of atom,and the effect of quantum will appear.So the quantum computation based on the rule of quantum physics atracts attention. It can not only solve many problems that the classical computer can not solve accurately, but also has many characters such as quickly responding speed、lower energy consuming、strong reserves and parallel computation et al. There are many physical implementment schemes for quantum computation. We study mainly the quantum dot project here.It has good application foreground because of it based on solid material,solid electron technology and cosmically integrate circuit. So it fits integration and miniaturization. But the interaction between the quantum dots is not strong. In order to strengthen the interaction among the quantum dots and reduce the decoherence, we adopt the method that combinates the quantum dot with the microcavity.Based on this model and the concept of distributed quantum computation, we introduce the scheme for physical implementment of quantum computation.Then we discuss concretely the preparation of quantum dot state, the implement of quantum gate,the complement of quantum measurement and the transmittion of quantum information.The main work of mine is: 1. We prepare the entanglement of quantum dot in microcavity by using 温州大学硕士学位论文 iv single photon. 2. We implement the controlled quantum teleportation in quantum dot system through the Faraday rotation induced by single photon. We use single photon to generate the entanglement between the photon and quantum dot spin. Then, we complete the controlled teleportation by measuring single photon to measure the quantum dot spin state. 3. We implement the quantum teleportation of quantum dot entangled state by single photon in quantum dot - microcavity. We complete the measurement of quantum dot spin state using single photon. It plays an important role in distributed quantum computation and also can enlarge the network of quantum computation. KEYWORDS: distributed quantum computer, quantum dot, entangled state, quantum teleportation 温州大学硕士学位论文 I 目录 第一章 量子计算及其物理实现简介....................................1 §1.1量子计算基本概念..............................................1 §1.1.1 量子比特................................................1 §1.1.2 量子门..................................................2 §1.1.3 量子计算的门组结构......................................4 §1.1.4.量子纠缠态..............................................6 §1.2量子计算的物理实现............................................9 §1.2.1 量子计算的物理实现条件.................................10 §1.2.2 量子计算的物理实现方案.................................10 本章小结..........................................................13 第二章 基于量子点的量子计算.......................................14 §2.1量子点方案...................................................14§2.2量子点量子计算实现情况.......................................16 §2.2.1 量子点量子比特的表示...................................16 §2.2.2 量子点系统中量子逻辑门的实现...........................16 §2.2.3 量子点系统中量子测量的实现.............. ............. 20 §2.3分布式量子计算...............................................22本章小结..........................................................23 第三章 量子点系统中纠缠态的制备...................................24 §3.1 腔-量子点系统中量子纠缠态的实现.............................24 §3.1.1 两量子点纠缠态的产生...................................24 §3.1.2 三量子点纠缠态的产生...................................25 §3.2 腔-量子点系统中的法拉第旋转与纠缠态的产生...................26 §3.2.1 法拉第效应.............................................26 §3.2.2 腔量子点系统里通过法拉第效应产生纠缠态.................26 本章小结..........................................................30 第四章 量子点方案中量子信息的传输.................................31 §4.1量子隐形传态的定义和发展.....................................31 §4.2腔-量子点系统中的可控的量子隐形传态..........................32 温州大学硕士学位论文 II §4.3 腔-量子。