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。     

基于纯态的量子通信系统模型

量子通信与量子计算已经引起人们极大的关注.对于量子态如何用于信息处理的问题,提出了量子通信的两种基本模型:量子直接通信模型与量子隐形传态通信模型.在量子直接通信模型中,用模块化的方法将量子通信全过程分为量子信源编译码,量子信道编译码,量子信道与量子噪声模块,并详细阐述了各个模块的功能与用途.在量子隐形传态通信模型中,利用量子隐形传态特性,通过将待传粒子与纠缠对的联合测量模块化为量子调制部分,给出了基于隐形传态的量子通信一般模型.量子通信在安全性及效率方面具有经典通信无法比拟的优势.     

利用二粒子纠缠态隐形传递未知二粒子量子态

提出了一个利用特殊的二粒子纠缠态作为量子信道来实现任意二粒子未知量子态的隐形传态。对比Yuan等人提出的利用[χ]纠缠态实现的任意未知二量子态的隐形传态方案。该方案利用二粒子信道和Bell基测量,以及特殊的幺正操作顺利完成信息的隐形传态。而且方案中利用了较少的资源,且获得的原始信息的概率为1。     

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。     

量子态的概率隐形传态

利用多方控制代理的网络,提出了一个量子隐形传态多量子位的协议。协议中所使用的量子信道有别于已有协议中所使用的量子最大纠缠态。得到的研究结果是,只有在发送方和多方代理合作时,接受方才能得到概率隐形传态的量子信息。因为使用的量子信道是非最大纠缠态,所以该协议更具有实际意义。     

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。     

以任意高维纠缠态为量子信道的受控隐形传态

目的是利用高维量子纠缠态为量子信道，讨论未知单粒子态的受控隐形传输问题。以三维量子纠缠态为信道，提出一个二维任意单粒子态的受控隐形传输协议。提出了以任意[d]-维量子纠缠态为量子信道，[t]-维任意单粒子态的隐形传输协议[(t相似文献   

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。     

多参数测量的分层量子态分享

融合了分层量子态分享及多参数测量思想，提出了一个研究不同最大纠缠量子信道的分层量子态分享可能性的新框架，并以4-粒子团簇态作为量子信道为例说明了该框架是可行的，指出该例是现有协议的推广。考虑到最大纠缠态的保持对现有技术的挑战，将上述框架推广到非最大纠缠信道的情形，且以4-粒子非最大纠缠团簇态为例，验证了这个推广框架用于研究不同非最大纠缠信道的分层量子态分享是可行的。进一步，分析了验证实例的成功概率（经典耗费）与测量参数或量子纠缠参数间的依赖关系，说明了可以根据量子信道的参数来调整测量基的参数，达到调节成功概率或经典耗费，满足真实世界中不同需求之目的。     

基于量子隐形传态的水下传感器网络分级加密通信协议

针对水下传感器网络中通信信息安全性与水声信道通信特性的不足,提出了一种基于量子隐形传态的水下传感器网络分级加密通信协议.一级在水面基站与自由水下航行器之间,采用量子隐形传态实现两者之间共享量子密钥,利用纠缠关联空间非定域性保证其通信信息安全性;二级在水下节点到水下自由航行器之间,采用对称加密算法实现两者之间信息的加密传输,利用对称加密快捷的优点提高其通信信息效率.分别对量子攻击、经典攻击及通信效率这3个方面进行了分析,证明该协议能有效防止量子态截获、重构、替换等攻击.     

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.     

Faithful teleportation via multi-particle quantum states in a network with many agents

An efficient scheme is proposed for faithful teleportation of an arbitrary unknown multi-particle state via multi-particle quantum states, in which the teleportation is completely deterministic providing that one can successfully construct a group of EPR pairs. Our scheme can effectively avoid possible destruction of the unknown state to be teleported, which however may occur in existing probabilistic teleportation schemes. In addition, we develop a scheme for establishing a faithful quantum channel for both indirect and direct teleportation multi-particle system, which can be applied in a teleportation network where intermediate agents exist between a sender and a receiver. Compared to the indirect construction of the faithful channel, the required auxiliary particle resources, local operations and classical communications in the direct construction scheme are considerably reduced.     

Cyclic quantum teleportation

We propose a scheme of cyclic quantum teleportation for three unknown qubits using six-qubit maximally entangled state as the quantum channel. Suppose there are three observers Alice, Bob and Charlie, each of them has been given a quantum system such as a photon or spin-\(\frac{1}{2}\) particle, prepared in state unknown to them. We show how to implement the cyclic quantum teleportation where Alice can transfer her single-qubit state of qubit a to Bob, Bob can transfer his single-qubit state of qubit b to Charlie and Charlie can also transfer his single-qubit state of qubit c to Alice. We can also implement the cyclic quantum teleportation with \(N\geqslant 3\) observers by constructing a 2N-qubit maximally entangled state as the quantum channel. By changing the quantum channel, we can change the direction of teleportation. Therefore, our scheme can realize teleportation in quantum information networks with N observers in different directions, and the security of our scheme is also investigated at the end of the paper.     

Teleportation of a qubit using entangled non-orthogonal states: a comparative study

The effect of non-orthogonality of an entangled non-orthogonal state-based quantum channel is investigated in detail in the context of the teleportation of a qubit. Specifically, average fidelity, minimum fidelity and minimum assured fidelity (MASFI) are obtained for teleportation of a single-qubit state using all the Bell-type entangled non-orthogonal states known as quasi-Bell states. Using Horodecki criterion, it is shown that the teleportation scheme obtained by replacing the quantum channel (Bell state) of the usual teleportation scheme by a quasi-Bell state is optimal. Further, the performance of various quasi-Bell states as teleportation channel is compared in an ideal situation (i.e., in the absence of noise) and under different noise models (e.g., amplitude and phase damping channels). It is observed that the best choice of the quasi-Bell state depends on the amount non-orthogonality, both in noisy and noiseless case. A specific quasi-Bell state, which was found to be maximally entangled in the ideal conditions, is shown to be less efficient as a teleportation channel compared to other quasi-Bell states in particular cases when subjected to noisy channels. It has also been observed that usually the value of average fidelity falls with an increase in the number of qubits exposed to noisy channels (viz., Alice’s, Bob’s and to be teleported qubits), but the converse may be observed in some particular cases.     

Splitting a quantum secret without the assistance of entanglements

The existing secret sharing schemes of sharing quantum information usually require the resource of entanglements no matter they are based on quantum teleportation or remote state preparation. However, in the practical applications, it is difficult to build faithful and stable entangled channels among many users. We show how the quantum information splitting and reconstruction can be implemented without the assistance of entanglements and give a quantum secret sharing protocol based on the theory of quantum interference. We also discuss its security against the individual attacks and generalize its three-party case into a multiparty case.