【作者】 周兰；

【导师】 匡乐满；

【作者基本信息】 湖南师范大学 ， 理论物理， 2005， 博士

【摘要】 随着信息技术和量子力学的发展,以量子力学为基本规律的量子信息学逐渐形成。由于量子力学的叠加原理大幅度的提高了计算效率,而且量子力学的非经典相关使得真正的保密通讯(永远不会被破译)成为可能,量子信息学倍受关注,并成为当今学术界非常关心的热门领域。量子信息的核心旨在巧妙地利用量子相干性(对多粒子系统表现为量子纠缠)对信息的新型载体——量子比特进行操纵控制,以非常规的方式进行信息的编码、存储和传递。如今理论上对量子信息处理的探讨进行得如火如荼,为了证明在信息操纵和信息传输上量子力学具有着非常巨大的潜力,人们也急切的寻找着能实现量子信息处理的物理系统。过去几十年中,由于光学系统在量子工程上的深厚基础以及光学探测技术的发展,光学系统早已成为检验量子力学基本原理的重要系统,如今又自然的成为了实现量子信息处理的首选系统。 本文研究典型纠缠态的产生与制备、纠缠的量度和纠缠的传送,以及以纠缠为基础的几个典型量子信息处理过程(包括量子隐形传态、量子博弈和量子无错鉴别)的光学实现。本文的主要创新结果如下: 1、利用量子比特的单光子表示,提出了实现包括Einstein-Podolsky-Rosen(EPR)态在内的两个量子比特的任意纠缠态的量子隐形传态的全线性光学实现方案。我们使用的线性光学元件分别是分束器、相移器和波片。这种全线性光学实现方案是基于单光子路径和极化都可以表示量子比特。该方案中我们总共使用了五个量子比特,其中四个是单光子的路径量子比特,一个是单光子的极化量子比特。 2、通过非线性光学元件与线性光学元件的组合,首次提出了一种更多还原

【Abstract】 With the development of information technique and quantum mechanics, a new subject based on the law of quantum mechanics-quantum information theory comes into being. Because of the large improvements in computational efficiency and communication security by exploiting the superposition principle and the non-classical correlation of quantum mechanics, quantum information theory soon attracts much attention and becomes the hottest areas of modern academe. It is the quantum coherence which lies at the heart of quantum information that makes the manipulation of information-carrier qubits possible, and the occurrence of the information coding, storing and transferring in a unconventionality way. Nowadays the processing of quantum information is theoretically under intense investigation, people are eagerly to find physical system to testify potential improvements offered by quantum mechanics to the manipulation and the transmission of information. Based on the substantial development in quantum engineering and measurement of light in the past decades, quantum optical systems are ideal for the experimental test of the foundation of quantum mechanics as well as for the experimental implementation of quantum information processing.This thesis investigates the generation and preparation of several typical entangled states, the measurement and transmission of entanglement, as well as the typical information processing based on entanglement which includes quantum teleportation, quantum game and error-free discriminations of quantum states. Our mainly work is as follow:(1) Based on the representation of multiple qubits by single photon, we present a linear optical implementation for quantum teleportation of an unknown two-qubit entangled state by using linear optical elements. The optical elements used here are beam splitters, phase shifters and wave plates. In this optical proposal, five qubits are involved, one of them are built by the polarization of single photon, which is called the polarization qubit, and the others are constructed by the paths where the single photon takes, which is called the location qubit.(2) Present a proposal for optically implementing the quantum game of the two-player quantum prisoner’s dilemma by using some linear and nonlinear optical elements. Further we present a feasible scheme by only using linear optical elements. The most important part of quantum Prisoner’s dilemma is player’s strategies and the gate which introduces entanglement. The strategies of each player are made up of two beam splitters and four phase shifters, and the entangling gate is consist of beam splitters, phase shifters and additional cross Kerr medium. In the further scheme of quantum prisoner’s dilemma, in addition to beam splitters and phase shifters, the quarter-wave plates and half-wave plates are used to realize the strategies and the entangling gate.(3) Give an optical method for optimal error-free discrimination of some linear independent states by the coupling of the original particle to an ancillary system. The two systems are represented by different degrees of freedom of a single photon, one is the photon’ s polarization, and the other is the photon’ s travelling paths. The apparatus we used here are polarized beam splitters, wave plates and single photon detectors.(4) Propose a method for optically creating entangled squeezed vacuum states (SVSs) by introducing a SVS-phase shifter whose possible realization is更多还原