本科毕业论文基于可变耦合率的单光子三极管

大连理工大学本科毕业设计（论文）基于可变耦合率的单光子三极管SinglePhotonTransistorBasedonVariableCoupling学院(系)：物理与光电工程学院专业：应用物理学学生姓名：徐爽学号：201022015指导教师：衣学喜评阅教师：李崇完成日期：2014年6月3日大连理工大学DalianUniversityofTechnology基于可变耦合率的单光子三极管-I-摘要单光子三极管是一种利用单光子控制光路透射率的非线性光学器件，实现这样的器件是量子光学领域长期未能实现的目标。这样的器件既可以作为单光子探测中的信号放大器，用以提高单光子探测的效率，也可以作为全光量子计算机中的受控量子门。光子是目前能实现量子信息长距离传输的唯一媒介，但它同时也具有难以测量和难以相互作用的缺点，单光子三极管的实现可以解决这些问题，这对于量子通讯和量子计算有重大意义。目前在单光子三极管方向已经有了很多研究，但仍未能实现有效的单光子三极管器件，其最大的挑战是实现三极管系统对单光子信号的有效吸收。以往的单光子吸收手段是采用控制激光，控制原子集群对单光子的吸收，这样的手段既不利于系统的小型化，也不利于提高效率。本文基于超导量子系统，利用谐振腔与波导之间的可变耦合率，通过对耦合率的控制，实现单光子三极管系统对单光子的有效吸收。吸收单光子后的系统的有效频率会发生变化，因而可以对多个光子的谐振反射进行控制。关键词：单光子三极管；全光量子计算；可变耦合率基于可变耦合率的单光子三极管-II-SinglePhotontransistorBasedonVariableCouplingAbstractSinglePhotonTransistorisanopticaldevicethatcontrolsthetransmissionrateofanopticalpathwithonesinglephoton.Todesignsuchadeviceisalongstandinggoalofquantumoptics.Suchdevicecouldserveassignalmagnifiersinsinglephotondetectorstoincreasedetectionrate.Itcouldalsoserveascontrolledquantumgatesinall-opticalquantumcomputation.Photonisthesinglebestmediaforlongdistancetransmissionofquantuminformation,butithasproblems.Singlephotonsarenoteasytodetectandtheyareincapableofeffectivelyinteractingwithoneanother.SinglePhotonTransistorcouldsolvetheseproblems,whichwouldgreatlyassistthedevelopmentofquantuminformation.Therehasbeenmanyresearchinthisarea,butaneffectivedesignhasyettoovercomeitsbiggestchallenge.Thatis,theeffectiveabsorptionofsinglephotonsignal.Manyhaveproposedtheuseofcontrolbeamonanensembleofatoms,butsuchmethodisneithereasytodownsizenorcapableofhighefficiency.Thispaperproposesasystembasedonsuperconductingsystemthatusecontrolledvariablecouplingbetweenaresonatorandawaveguidetoeffectivelyabsorbasinglephoton.Absorbedphotonwouldchangetheeffectivefrequencyofthesystem,andthuscouldcontroltheresonanttransmissionofmultiplephotons.KeyWords：SinglePhotontransistor；All-OpticalQuantumComputation；VariableCoupling基于可变耦合率的单光子三极管-III-目录摘要.........................................................................................................................................IAbstract......................................................................................................................................II引言............................................................................................................................................11知识基础................................................................................................................................31.1量子力学.....................................................................................................................31.1.1量子态与态叠加原理......................................................................................31.1.2表象、算符与薛定谔方程..............................................................................41.1.3全同粒子的交换不变性..................................................................................51.2二次量子化.................................................................................................................51.2.1粒子数表象......................................................................................................51.2.2Fock空间与产生湮灭算符.............................................................................62背景知识................................................................................................................................72.1量子信息.....................................................................................................................72.1.1量子比特..........................................................................................................72.1.2Bell态...............................................................................................................72.1.3量子密码通讯..................................................................................................82.1.4量子计算机......................................................................................................92.2腔量子电动力学.......................................................................................................102.2.1一维光场与光腔的描述................................................................................102.2.2光腔、光场和原子的相互作用....................................................................112.3超导量子系统...........................................................................................................112.3.1超导与Cooper电子对..................................................................................112.3.2超导量子比特................................................................................................122.4电磁诱导透明...........................................................................................................132.4.1现象和原理....................................................................................................132.4.2推广应用........................................................................................................143基于可变耦合率的单光子三极管方案.....................................................