二粒子和三粒子纠缠态的控制隐形传态研究.pdf

二粒子和三粒子纠缠态的控制隐形传态研究.pdf华中科技大学硕士学位论文二粒子和三粒子纠缠态的控制隐形传态研究姓名:彭涛申请学位级别:硕士专业:凝聚态物理指导教师:商育民20070602华中科技大学硕士学位论文I摘要量子信息学是由量子力学和信息科学相结合而形成的一门新兴学科,主要包括量子通信和量子计算两个方面。在量子信息学中,量子纠缠态是其最基本的要素,而以它为基础的一些研究方向如量子隐形传态已取得了重要的突破。量子隐形传态构成了量子通讯和量子计算的重要内容,对量子隐形传态的深入研究将对量子信息学的基本原理和未来信息通信产生深远的影响,并将进一步揭示出量子力学的物理内涵。本文运用纠缠态和量子信息,研究了隐形传态和控制隐形传态,把一种有别于GHZ态和W态的三体纠缠态作为量子信道,经过计算发现:这种三体纠缠态也能作为二粒子一般态的隐形传态中作为量子信道,实现隐形传态。论文后面部分研究控制隐形传态。在二粒子一般态的控制隐形传输中,构建一个最大EPR态和一个最大四粒子纠缠态并以此为量子信道,结果发现也能实现控制隐形传输。在二粒子一般态的两人控制的控制隐形传输方案也作了讨论:当两个控制方都合作时,接收方完全可以获得发送方所传送的量子态;当有一方不合作或两方都不合作时,接收方获得发送方要传的量子态的保真度与未知量子态的系数有关;当发送方所传输的量子态是二粒子的最大纠缠态时,不管控制方是否参与合作,接收方都能以100%的概率获得发送方传输的量子态。这和其它方案的结果是不同的。我们还讨论了有n个控制方参与的情况下三粒子一般态的控制隐形传态,计算了接收方获得发送方要传的量子态的保真度与未知量子态的系数之间得关系,得出了和以其他纠缠态作为量子信道时不同的结论。关键词:纠缠态隐形传态控制隐形传态量子信道保真度华中科技大学硕士学位论文IIAbstract The quantum information science is an emerging bined by the quantum mechanics and the information science. It includes the munication and the putation. In the quantum information science, the quantum entanglement is essential. Based on it, some area such asthe quantum teleportation has been obtained important breakthrough. Thequantum teleportation constituted the important content of the munication and the putation. Deep researches on the quantum teleportation will profoundly influence on the basic principle of the quantum information and on the future of quantum munication, and will further reveal the physics connotation of the quantum mechanics. In this thesis, by using the quantum entanglement and the quantum information, putations on the teleportation and the controlled teleportation were performed. A new kind of three-particle entanglement that different from the GHZ state and W state was chose as the quantum channel in the teleportation. Through putation, it could also achieve the teleportation of two-particle general state with the three-particle entanglement as the quantum channel. Our attention was on the controlled teleportation. The controlled teleportation of two-particle general state with one largest EPR sta