共查询到20条相似文献,搜索用时 111 毫秒
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我们利用单个II类相位匹配OPA产生的双模压缩态实现连续变量压缩纠缠态,完成了连续变量量子离物传态.利用II类相位匹配OPA参量缩小过程可以实现正交振幅反关联、正交位相关联的压缩纠缠态,与运转于阈值以下的OPO产生的正交振幅关联、正交位相反关联的压缩纠缠态相比,这种纠缠可以采用直接平衡测量的方法完成Bell态测量.利用双KTP补偿非线性过程的离散效应,获得了最大压缩大于2 dB的双模压缩纠缠态,采用直接测量的方法,我们完成了真空场正交分量的离物传送.探测器探测效率93%,保真度达到0.59.采用这种方案简化了测量方法与纠缠光源产生装置,有利于进行量子通信的实验研究与应用. 相似文献
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基于Braunstein和Kimble提出的B-K方案以双模最小关联混合态作为量子信道实施对未知量子态的隐形传送,并以传送相干态为例进行了研究.结果表明:双模最小关联混合态作为一种广义的Einstein-Podolsky-Rosen型纠缠态在实现量子隐形传态中能很好地担当量子信道的角色,在纠缠度和压缩度选择适当的条件下被传送未知量子态的保真度可以达到1.这是比双模压缩真空态更优越的量子信道.
关键词:
量子隐形传态
双模最小关联混合态
保真度 相似文献
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在振幅阻尼信道上进行量子隐形传态的过程中, 量子Bell纠缠态将发生退相干, 导致隐形传态质量下降甚至通信失败. 为克服该影响, 本文提出了一种Bell纠缠态补偿方法. 在估计振幅阻尼信道参数的基础上, 将对纠缠态的补偿分为纠缠退相干发生之前的预补偿以及 经历量子振幅阻尼信道之后的匹配补偿两部分. 前者在纠缠源处进行, 后者在两个量子通信 用户处进行, 预补偿及匹配补偿参数与信道特性参数相关. 纠缠补偿完成后, 再进行隐形传态. 理论推导与性能分析结果表明, 相比于不进行纠缠补偿及仅在发生退相干之后进行的纠缠补偿, 本方法能够获得更高的隐形传态保真度, 适当调整补偿参数, 可使保真度接近于1, 对克服纠缠 退相干带来的隐形传态质量下降问题具有一定的意义. 相似文献
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基于Braunstein和Kimble方案以双模压缩真空态作为量子信道实施对单模最小关联混态量子隐性传态的可行性进行了研究.我们发现,单模最小关联混态在一定参数范围内呈现出压缩效应这种非经典性质,利用双模压缩真空态作为量子通道可以高保真的传递没有压缩效应的单模最小关联混态,但对呈现压缩效应的单模最小关联混态进行量子隐性传送时得到输出态的保真度较低.而且发现通过调节输出端位移因子的方法不能实现对单模最小关联混态保真度的优化. 相似文献
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平衡零拍探测是测量量子光场的重要方法之一. 通过对相位灵敏光学参量放大器注入的信号进行位相调制, 然后利用平衡零拍探测系统测量光学参量放大器输出的压缩光. 将相位灵敏光学参量分别运转在参量放大和参量缩小, 通过观察噪声谱中的调制信号就可确定测量的量子光场是正交振幅或位相分量. 通过解调位相调制信号可获得误差信号, 实现锁定平衡零拍探测系统本底光与待测光场相对位相为零(对应于待测光场振幅噪声分量).
关键词:
平衡零拍探测
位相锁定 相似文献
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Based on tensor representation and Bell basis measurement in bidirectional quantum teleportation, a criterion that can be used to judge whether a four-qubit quantum state can be regarded as quantum channel or not in bidirectional teleportation is suggested and a theoretical scheme of bidirectional teleportation via four-qubit state as the quantum channel is proposed. In accordance with this criterion we give a general method of selecting quantum channel in bidirectional teleportation, which is determined by the channel parameter matrix R in the Bell basis measurement. This general method provide a theoretical basis for quantum channel selection in bidirectional quantum teleportation experiments. 相似文献
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Implementation of nonlocal Bell-state measurement and quantum information transfer with weak Kerr nonlinearity 下载免费PDF全文
We propose a protocol to implement the nonlocal Bell-state measurement, which is nearly determinate with the help of weak cross-Kerr nonlinearities and quantum non-destructive photon number resolving detection. Based on the nonlocal Bell-state measurement, we implement the quantum information transfer from one place to another. The process is different from conventional teleportation but can be regarded as a novel form of teleportation without entangled channel and classic communication. 相似文献
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We investigate experiments of continuous-variable quantum information processing based on the teleportation scheme. Quantum
teleportation, which is realized by a two-mode squeezed vacuum state and measurement-and-feedforward, is considered as an
elementary quantum circuit as well as quantum communication. By modifying ancilla states or measurement-and-feedforwards,
we can realize various quantum circuits which suffice for universal quantum computation. In order to realize the teleportation-based
computation we improve the level of squeezing, and fidelity of teleportation. With a high-fidelity teleporter we demonstrate
some advanced teleportation experiments, i.e., teleportation of a squeezed state and sequential teleportation of a coherent
state. Moreover, as an example of the teleportation-based computation, we build a QND interaction gate which is a continuous-variable
analog of a CNOT gate. A QND interaction gate is constructed only with ancillary squeezed vacuum states and measurement-and-feedforwards.
We also create continuous-variable four mode cluster type entanglement for further application, namely, one-way quantum computation. 相似文献
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量子隐形传态的杰出安全特性使其在未来的通讯领域充满潜力.量子力学的不确定性原理和不可克隆定理禁止对量子态进行直接复制,因此,量子隐形传态将量子态划分为经典和量子两部分,信息分别经由经典和量子通道从发送者Alice传递给远方的接收者Bob,根据这两种信息,Bob实行相应操作就可以以一定的几率重建初始传送态.利用一般意义的隐形传态方案,提出一种简便的新方法实现了一个N粒子任意态的概率传态.方法采用N个非最大纠缠的三粒子GHZ态作为量子通道,避免了引入额外的辅助粒子.为了实现传态,Alice将所有粒子分成N份,对第i份的粒子对(i,xi)实行Bell测量并将结果通过经典通道通知Bob,Bob对粒子(yi,zi)进行相应的操作就可以完成第i个粒子信息的传送.当完成N次相似的重复操作后,Bob就可以准确地重建初始传送态.文中以Bell态测量为基本手段,重复的操作同时也降低了实验难度,作为一个特例,文中给出了一个两粒子任意态的传态方案. 相似文献
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We provide various schemes for quantum teleportation by using the four and five qubit cluster states. Explicit protocols for the perfect quantum teleportation of three and four qubit states are illustrated. It is found that the four-qubit cluster state can be used for perfect quantum teleportation of a special form of three-qubit state and the five-qubit cluster state can be used for perfect quantum teleportation of a special form of four-qubit state. 相似文献
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Xiang Chen 《中国物理 B》2022,31(3):30302-030302
Teleportation is a quantum information process without classical counterparts, in which the sender can disembodiedly transfer unknown quantum states to the receiver. In probabilistic teleportation through a partial entangled quantum channel, the transmission is exact (with fidelity 1), but may fail in a probability and the initial state is destroyed simultaneously. We propose a scheme for nondestructive probabilistic teleportation of high-dimensional quantum states. With the aid of an ancilla in the hands of the sender, the initial quantum information can be recovered when teleportation fails. The ancilla acts as a quantum apparatus to measure the sender's subsystem. Erasing the information recorded in it can resume the initial state. 相似文献
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提出一种量子投票协议, 协议基于非对称量子通道受控量子局域幺正操作隐形传输(quantum operation teleportation, QOT). 由公正机构CA提供的零知识证明的量子身份认证, 保证选民身份认证的匿名性. 计票机构Bob制造高维Greenberger-Horne-Zeilinger 纠缠态建立一个高维量子通信信道. 选民对低维的量子选票进行局域幺正操作的量子投票, 是通过非对称基的测量和监票机构Charlie的辅助测量隐形传输的. Bob在Charlie帮助下可以通过幺正操作结果得到投票结果. 与其他一般的QOT量子投票协议相比, 该协议利用量子信息与传输的量子信道不同维, 使单粒子信息不能被窃取、防止伪造.选举过程由于有Charlie的监督, 使得投票公正和不可抵赖.由于量子局域幺正操作隐形传输的成功概率是1, 使量子投票的可靠性得以保证.
关键词:
量子投票
高维GHZ纠缠态
非对称基测量
量子操作隐形传输 相似文献