以最大slice 态为信道的受控量子远程控制

利用三量子最大slice态作为量子信道,提出了单量子酉算子的受控远程执行的两个协议。首先,利用双向量子隐形传态(BQST),给出了一个任意单量子酉算子的受控隐形传输方案。结果表明,通过非最大纠缠信道,发送者能够在遥远的接受者的量子系统上远程地执行一个任意单量子酉算子。如果发送者和控制者对各自量子执行恰当的投影测量,那么量子算子的受控远程执行的成功概率就能达到1。其次,提出了一种不使用BQST方法的部分未知算子的受控远程控制协议。此协议因部分未知算子取自于两个限制集,减少了量子纠缠和经典通信耗费。在这些方案中,当且仅当控制者愿意帮助接受者远程操作,量子算子的受控远程执行才能完成。     

三维单粒子态的双向受控隐形传态

以事先分享的两个广义最大纠缠GHZ态为量子信道,提出了一个三维单粒子态双向受控隐形传态协议。在该协议中,遥远的两方可以在第三个遥远方的控制下同时、确定性地交换他们的三维单粒子态,这种交换在没有控制者的许可下是不会成功的。为了推广这一协议,采用投影测量和正算子值测量,分别提出了两个双向受控的三维单粒子态隐形传输协议。在这两个协议中,两个广义非最大纠缠GHZ态被用作量子信道来连接三个合法参与者,量子任务总能以一定的概率来完成。     

基于多参数测量的双向受控隐形传态

融合了双向隐形传态、受控隐形传态、概率隐形传态及多参数测量思想,提出了一个新的双向受控概率隐形传态协议。在该协议中,以五粒子非最大纠缠团簇态为信道,发送者采用多参数通用测量,接收者引入辅助粒子,并在控制者的允许下,利用测量信息施行适当酉变换,就能以一定概率同时交换他们的量子态。分析了成功概率（经典耗费）与量子纠缠参数及测量参数间的依赖关系,说明了该协议可以根据量子信道的参数来调整多参数测量的参数,达到调节成功概率或经典耗费,满足真实世界中多种不同需求的目的。此外,该协议是经典双向受控隐形传态的推广。     

基于极化单光子的高效安全量子秘密共享方案

为进一步提高量子秘密共享协议的效率和安全性,结合量子Grove搜索算法提出一种基于极化单光子的量子秘密共享协议.效率分析结果表明,该方案可以将全部量子态用于密钥共享,理论效率为100%.在方案的安全性证明中,借助量子Grove算子和量子纠缠特性得出方案能够有效抵抗中间人攻击,同时该方案利用辅助量子态进行监视,能够以高概率检测特洛伊木马攻击.通过对Grove算子进行高维推广,证明了方案推广到(n,n)的可行性和实用性.     

基于受控旋转门的量子神经网络模型算法及应用

提出一种量子神经网络模型及算法．首先借鉴受控非门的含义提出一种受控量子旋转门,基于该门的物理意义,提出一种量子神经元模型,该模型包含对输入量子比特相位的旋转角度和对旋转角度的控制量两种设计参数;然后基于上述量子神经元提出一种量子神经网络模型,基于梯度下降法详细设计了该模型的学习算法：最后通过模式识别和时间序列预测两个仿...     

任意二粒子纠缠态的受控量子通信

为了解决任意二量子通信问题,首先给出了五粒子和七粒子纠缠态的构造方法,并提供了它们的量子线路图。其次,以该五粒子纠缠态为量子信道,提出一个任意二粒子未知量子态的受控隐形传态协议。该协议在监察者Charlie的控制下,Alice进行四粒子投影测量和经典通信,Bob采用简单酉变换就能以100%的概率成功重构一个任意二粒子纠缠态。最后,利用七粒子纠缠态为量子信道,提出了任意二粒子纠缠态的联合受控远程制备方案。在此方案中,发送者Alice用自己掌握被制备态的部分信息构造测量基,发送者Bob采用前馈测量策略,接收者Diana在监控者Charlie的帮助下,通过简单幺正变换就能确定性地恢复原始态。     

GHZ态的多参数测量控制概率隐形传态

量子隐形传态大多都使用最大化纠缠态作为量子信道,但最大化纠缠资源只存在于理想情况下。研究了非最大化纠缠信道的量子隐形传态,基于非最大化纠缠GHZ态提出了一个新型的概率控制隐形传态方案。通过引入多参数通用测量,可以根据量子信道参数调整测量基参数,进而实现最佳的成功概率。加入了量子控制者,使方案具有更高的灵活性。该方案可以被扩展到接收者没有足够量子能力的半量子通信情况,进一步扩大了概率隐形传态的应用范围。     

通用的量子同态加密框架

研究了量子同态加密,提出了一种通用的构造量子同态加密算子的方法,进而建立了构造量子同态加密方案的一种通用框架;通过二值和三值量子态的酉变换,利用该框架构造了相应的量子同态加密方案,与现有文献的构造方案相比,利用该框架构造的量子同态加密方案更具有普遍性;通过安全性分析,该框架的安全性是基于加密算法的安全性和密钥的安全性。由于该框架采用了对称量子加密算法,导致构造量子同态算子时需要加密密钥,从而该框架是一种弱的对称量子同态加密框架。最后,该框架被推广到了量子公钥加密的情形。     

基于概率幅编码的混合量子演化算法

个体基于量子概率幅进行编码,并将经典遗传算法的杂交算子用于量子演化算法中演化目标的优化,提出了混合量子演化算法。算法中对量子旋转角自适应更新,并首次引入了突变度的概念定义了自适应的变异算子,对量子个体的演化目标定期实施杂交,有效地交换并利用了演化信息,避免了未成熟收敛,提高了算法效率。数值优化问题的实验结果表明该算法优于QEA和CGA,并能以极大概率成功地解决“大海捞针”问题,且计算效率高,优化速度与CGA相当。     

Toffoli门及相位估计的分解

给出了Toffoli门和量子相位估计第一阶段运算P这两个受控运算的分解及相应的图示说明,使得人们可以更好地从矩阵论和算子论的角度理解与应用Toffoli门和量子相位估计。     

Tripartite quantum operation sharing with two asymmetric three-qubit W states in five entanglement structures

Tripartite remote sharing of any single-qubit operation with two asymmetric three-qubit W states is amply treated. Five schemes are put forward with the W states in five different entanglement structures corresponding to five different distributions of two identical qubit trios in three locations. For all schemes, two features about the security and the agent symmetry are analyzed and confirmed. Moreover, resource consumption, necessary-operation complexity, success probability and efficiency are also worked out and compared mutually. For all schemes, quantum resource consumption and necessary-operation complexity are same. The last scheme needs to cost two additional classical bits than the former four schemes. Nonetheless, the last scheme is deterministic and has the highest efficiency in contrast to the other four probabilistic schemes with lower efficiencies. Through some analyses, it is found that both success probability and intrinsic efficiency of each scheme are completely determined by the corresponding entanglement structure of the two W states. The underlying physics of this feature is revealed. In addition, the implementation feasibility of all the schemes is analyzed and thus confirmed according to the current experimental techniques.     

Probabilistic teleportation via multi-parameter measurements and partially entangled states

In this paper, a novel scheme for probabilistic teleportation is presented with multi-parameter measurements via a non-maximally entangled state. This is in contrast to the fact that the measurement kinds for quantum teleportation are usually particular in most previous schemes. The detail implementation producers for our proposal are given by using of appropriate local unitary operations. Moreover, the total success probability and classical information of this proposal are calculated. It is demonstrated that the success probability and classical cost would be changed with the multi-measurement parameters and the entanglement factor of quantum channel. Our scheme could enlarge the research range of probabilistic teleportation.     

Shared quantum control via sharing operation on remote single qutrit

Two qubit-operation-sharing schemes (Zhang and Cheung in J. Phys. B 44:165508, 2011) are generalized to the qutrit ones. Operations to be shared are classified into three different classes in terms of different probabilities (i.e, 1/3, 2/3 and 1). For the latter two classes, ten and three restricted sets of operations are found out, respectively. Moreover, the two generalized schemes are amply compared from four aspects, namely, quantum and classical resource consumption, necessary-operation complexity, success probability and efficiency. It is found that the second scheme is overall more optimal than the first one as far as three restricted sets of operations are concerned. Moreover, the experimental feasibility of our schemes is confirmed with respect to the nowaday technique.     

Quantum operation sharing with symmetric and asymmetric W states

Two tripartite schemes for sharing a single-qubit operation on a remote target state are proposed with symmetric and asymmetric W states, respectively. They are treated and compared from the aspects of quantum resource consumption, operation complexity, classical resource consumption, success probability and efficiency. It is found that the first scheme is better than the second one. In particular, the sharing can be achieved probabilistically with the first scheme while deterministically with the second one.     

Continuous-variable quantum network coding for coherent states

As far as the spectral characteristic of quantum information is concerned, the existing quantum network coding schemes can be looked on as the discrete-variable quantum network coding schemes. Considering the practical advantage of continuous variables, in this paper, we explore two feasible continuous-variable quantum network coding (CVQNC) schemes. Basic operations and CVQNC schemes are both provided. The first scheme is based on Gaussian cloning and ADD/SUB operators and can transmit two coherent states across with a fidelity of 1/2, while the second scheme utilizes continuous-variable quantum teleportation and can transmit two coherent states perfectly. By encoding classical information on quantum states, quantum network coding schemes can be utilized to transmit classical information. Scheme analysis shows that compared with the discrete-variable paradigms, the proposed CVQNC schemes provide better network throughput from the viewpoint of classical information transmission. By modulating the amplitude and phase quadratures of coherent states with classical characters, the first scheme and the second scheme can transmit \(4{\log _2}N\) and \(2{\log _2}N\) bits of information by a single network use, respectively.     

Schemes for remotely preparing an arbitrary four-qubit \chi -state

Two schemes via different entangled resources as the quantum channel are proposed to realize remote preparation of an arbitrary four-particle \(\chi \) -state with high success probabilities. To design these protocols, some useful and general measurement bases are constructed, which have no restrictions on the coefficients of the prepared states. It is shown that through a four-particle projective measurement and two-step three-particle projective measurement under the novel sets of mutually orthogonal basis vectors, the original state can be prepared with the probability 50 and 100 %, respectively. And for the first scheme, the special cases of the prepared state that the success probability reaches up to 100 % are discussed by the permutation group. Furthermore, the present schemes are extended to the non-maximally entangled quantum channel, and the classical communication costs are calculated.     

An efficient quantum blind digital signature scheme

Recently, many quantum digital signature (QDS) schemes have been proposed to authenticate the integration of a message. However, these quantum signature schemes just consider the situation for bit messages, and the signing-verifying of one-bit modality. So, their signature efficiency is very low. In this paper, we propose a scheme based on an application of Fibonacci-, Lucas- and Fibonacci-Lucas matrix coding to quantum digital signatures based on a recently proposed quantum key distribution (QKD) system. Our scheme can sign a large number of digital messages every time. Moreover, these special matrices provide a method to verify the integration of information received by the participants, to authenticate the identity of the participants, and to improve the efficiency for signing-verifying. Therefore, our signature scheme is more practical than the existing schemes.     

基于QDP的蝶形量子网络编码方案

当前已有的蝶形量子网络方案多数只能完成量子态经公共信道进行交叉传输,并且为实现蝶形网络的量子态无损传输,通常需要消耗纠缠资源。结合量子直接传态方案中态传输的方法,提出一种在蝶形网络中传输任意已知单量子态的网络编码方案。利用处于基态的单粒子作为量子寄存器,实现每个接收节点均能同时接收到来自全部发送节点发送的不同量子态。整个通信过程不需要使用纠缠资源和测量操作,仅通过各节点执行相关酉操作即可完成通信。并且将该方案扩展至采用多种形式的量子态作为寄存器以及发送节点和接收节点个数更多的情况。     

Joint remote state preparation of arbitrary two-particle states via GHZ-type states

The protocols for joint remote preparation of an arbitrary two-particle pure state from a spatially separated multi-sender to one receiver are presented in this paper. We first consider the situation of two sender and demonstrate a flexible deterministic joint remote state preparation compared with previous probabilistic schemes. And then generalize the protocol to multi-sender and show that by only adding some classical communication the success probability of preparation can be increased to four times. Finally, using a proper positive operator-valued measure instead of usual projective measurement, we present a new scheme via two non-maximally entangled states. It is shown that our schemes are generalizations of the usual standard joint remote state preparation scheme and more suitable for real experiments with requirements of only Pauli operations.