目录摘要..........................................................................................................1Abstract..................................................................................................2第1章绪论.............................................................................................31.1研究背景.........................................................................................31.2国内外研究现状..............................................................................31.3研究意义.........................................................................................4第2章量子计算与量子门操作................................................................6第3章在理想情况下远程制备四比特团簇态..........................................8第4章在去极化噪声下远程制备四比特团簇态....................................124.1密度算符的表征.............................................................................124.2输出态..........................................................................................124.3保真度分析....................................................................................15第5章结论...........................................................................................17第6章研究展望....................................................................................18参考文献.................................................................................................19致谢........................................................................................................22摘要本文中采用了团簇态作为量子信道，讨论了在去极化噪声下对与远程制备四比特团簇态所产生的影响。首先分析了在理想情况下远程制备四比特团簇态，Alice作为制备者，使用团簇态作为量子信道，经过构造合适的测量基进行两次测量，将测量结果发送给Bob，Bob再将接收到的团簇态通过引入辅助粒子的方式将原本要制备的四比特团簇态进行还原。接着讨论了在去极化噪声影响下远程制备四比特团簇态，并且通过保真度分析来探讨四比特团簇态的制备在理想情况下和实际应用中差异程度。关键词：团簇态；去极化噪声；保真度；远程制备AbstractClusterstatesareusedasquantumchannelsinthispaper.Theeffectsofremotelypreparedfour-bitclusterstatesondepolarizationnoisearediscussed.Firstly,weanalyzedtheremotepreparationoffour-bitclusterstatesunderidealconditions.Alice,asthefabricator,usestheclusterstateasthequantumchannel,performstwomeasurementsafterconstructinganappropriatemeasurementbase,andsendsthemeasurementresultstoBob,whowillthenreceivethemeasurementresults.Theclusterstatesobtainedbytheintroductionoftheauxiliaryparticlesrestorethefour-bitclusterstateoriginallytobeprepared.Thentheremotepreparationoffour-bitclusterstatesundertheinfluenceofdepolarizationnoise,andthedegreeofdifferenceinthepreparationoffour-bitclusterstatesunderidealconditionsandpracticalapplicationsbyfidelityanalysisarediscussed.Keywords:Clusterstate；Depolarizationnoise；Fidelity；Remotepreparation第1章绪论1.1研究背景如今，科学技术高速发展带动人类社会进入到信息时代，信息的传递俨然成为时代发展的重要推动力。同时，基于量子力学和经典信息科学的量子信息学，在过去几十年里也得到了快速地发展，并极大地影响了现代科学的发展方向。一方面，量子密钥分发[1]，量子秘密共享（QSS）[2]，量子数据隐藏[3-4]，量子签名[5]和量子认证[6]等量子密码手段可以实现相比经典通信更高水平的安全性[7-12]。另一方面，量子算法，如Grovers搜索算法[13]，可以实...
