N粒子量子纠缠态的隐形传送

该文提出了一个利用N对二粒子纠缠态作为量子通道实现N粒子纠缠态的隐形传送的方案.发送者对需传送的N粒子量子态与属于自己的纠缠对中的粒子分别进行N次Bell基测量,并将测量结果通过经典通道告诉接受者,接受者根据这些信息对自己拥有的N个粒子进行相应的联合幺正变换,可使这N个粒子处于待发送的原始量子态,从而实现概率为1的量子态的隐形传送.     

通过四比特 态实现任意量子态的量子隐形传态方案

提出了一个将四比特|χ〉态作为量子通道实现任意单量子比特和两量子比特的量子态的隐形传送方案.该方案依赖于两个通信站点之间的纠缠.在这个方案里,我们给出了Alice的测量结果以及Bob进行的相应的幺正操作,计算结果表明,该隐形传送方案是完美的,也就是说它的成功概率可达到1.此外,该方案中用到的测量以及纠缠通道的制备在目前的技术下是完全可行的.因此,我们的方案有望在实验上实现.     

通过纠缠交换实现N粒子任意态的概率传态

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,x_i)实行Bell测量并将结果通过经典通道通知Bob,Bob对粒子(y_i,z_i)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.     

利用三粒子W态隐形传送三粒子GHZ态

提出一个三粒子GHZ(Greenberger-Horne-Zeilinger)态从发送者传送给两个接收者中任意一个的量子隐形传送方案。此方案用两个三粒子W态作为量子信道。若发送者进行两次贝尔态测量和阿达码门操作,想得到所需传送的三粒子GHZ态的接收者引进一个辅助粒子,进行控制-非操作,同时根据另一个接收者的测量结果实施一个适当的幺正变换操作,可以一定的概率成功地隐形传送三粒子GHZ态。同时,此方案可推广至隐形传送n粒子GHZ态,这时也只需用两个三粒子W态作为量子信道,但这时想得到所需传送的n粒子GHZ态的接收者需引进(n-2)个辅助粒子,进行(n-2)次控制非操作,同时根据另一个接收者的测量结果实施一个适当的幺正变换操作,可以一定的概率成功地隐形传送n粒子GHZ态。     

通过四比特|χ〉态实现任意量子态的量子隐形传态方案（英文）

提出了一个将四比特|χ〉态作为量子通道实现任意单量子比特和两量子比特的量子态的隐形传送方案.该方案依赖于两个通信站点之间的纠缠.在这个方案里,我们给出了Alice的测量结果以及Bob进行的相应的幺正操作,计算结果表明,该隐形传送方案是完美的,也就是说它的成功概率可达到1.此外,该方案中用到的测量以及纠缠通道的制备在目前的技术下是完全可行的.因此,我们的方案有望在实验上实现.     

基于六粒子最大纠缠态的双向控制隐形传态方案(英文)EI北大核心CSCD

提出了一个利用六粒子最大纠缠态作为纠缠资源的双向量子控制隐形传态方案.该理论方案中,六粒子最大纠缠态作为量子通道来连系着合法的三方——通信双方和控制方,通信双方既是发送方同时也是接收方.传输过程中,Alice传输一个任意单粒子态a给Bob的同时Bob也传输一个任意的单粒子态b给Alice;由控制方Charlie来控制和协助通信双方完成最终的量子态的交换;Bob先对自己手中的粒子作一个幺正操作,用户双方再各自对自己手中的粒子执行Bell基测量,测量完成后通过经典信道将自己的测量结果公开宣布,用户双方根据对方所公布的测量结果做相应的幺正操作,从而成功地实现双向量子控制隐形传态.     

三粒子任意态的量子隐形完全传送

提出一个利用六粒子非贝尔对量子通道对一个任意的三粒子量子态进行隐形传送的方案.发送者Alice对需传送的三粒子量子态与属于自己的纠缠对中的三粒子进行三次Bell基测量,并将测量结果通过经典通道告诉接受者,接受者Bob根据这些信息对自己拥有的粒子进行Toffoli变换,就可使这三粒子处于待发送的原始量子态,从而实现概率为1的量子态隐形传送.利用变换算符的思想,很容易得出塌陷态的表达式以及接受者Bob所做的幺正变换的表达式.     

未知高维量子态的概率隐形传送

研究了未知的多维量子态的概率量子隐形传送问题.文中提出利用一个部分的三维两粒子纠缠态作为量子通道,概率传送未知的三维单粒子态的方案;然后通过利用两个部分的三维两粒子纠缠态作为量子通道,又提出了一种概率隐形传送未知的三维两粒子纠缠态的方案.并且对它们进行了推广:通过利用N个部分的d维两粒子纠缠态作为量子通道,可以把这种方案直接推广到未知的d维N粒子纠缠态的概率量子隐形传送.同样地,我们详细地列出了每个接收者所用的各种幺正变换.这样,我们就把未知的两维量子态的概率量子隐形传送问题研究推广到三维或多维量子态的概率量子隐形传送.与先前的研究方案相比,本文所提方案具有下列优点:处理方法不同,具体地说是在隐形传送的过程中所利用的幺正变换形式不同.在我们的方案中,接收者将引进一个具有初态为|0》A的d-维辅助粒子A,幺正变换U2采用d2×d2矩阵形式(对三维量子态来说d=3);而先前方案的接收者引进的是一个具有初态为|0》A的两维辅助粒子A,幺正变换U2采用2d×2d矩阵形式,即实际上就是过去方案的形式.也就是说,他们对其它粒子是进行多维处理,而对接收者引进的辅助粒子A只进行两维处理.     

未知三粒子GHZ纠缠态的网络多人控制传送

提出一种多人控制的三粒子GHZ纠缠态的量子隐形传送方案,为了实现传送,Alice需要对自己的三对粒子实施Bell测量并将结果通知Bob,异地的众多监控者对各自的控制位粒子实施Hadamard变换和投影测量.接受者Bob在Alice和所有监控的者发送的经典信息的协助下只需要施行简单的幺正变换就能成功实现量子态的隐形传送,传送过程中任意一个参与者的缺席都将导致传送的失败.     

利用三粒子W态隐形传送任意三粒子W态

提出一个任意三粒子W态从发送者传送给两个接收者任意一个的量子隐形传送方案.该方案用三个三粒子W态作为量子信道,且有两种方法实现传送目的.若发送者进行三次Bell态测量,想得到所需传送三粒子W态的接收者根据发送者的Bell态测量结果和另一个接收者在计算基{|0>,|1>}下的测量结果实施适当的幺正变换操作,就可以一定概率成功地隐形传送三粒子W态;分析表明如果改变操作秩序,成功实现量子隐形传态的概率不会受到影响.同时,该方案可推广至隐形传送N(N≥4)粒子W态,这时需要用N个三粒子W态作为量子信道.发送者做N次Bell态测量,接收者根据如前所述的所有测量结果实施相应的幺正变换,即可完成对N粒子W态的隐形传送.     

Probabilistic Teleportation of n-Particle State via n Pairs of Entangled Particles

The teleportation of an arbitrary n-particle state is proposed when n pairs of entangled particles are utilized as quantum channels. It can be successfully realized with a certain probability which is determined by the smallest coefficients of n entangled pairs. Using a Latin square of order 2ⁿ, explicit expressions of two unitary operations corresponding to different Bell-basis measurements performed by Alice can be obtained at the end of Bob.     

N粒子W纠缠态的隐形传输

提出使用纠缠交换的方法,采用N对二粒子非最大纠缠态作为量子通道来传输N粒子W纠缠态的方案。传输过程中,发送者对自己所拥有的粒子进行Bell基测量,并将测量结果通过经典通道通知接收者,接收者根据所获取的信息对她的粒子实行相应的幺正变换以恢复最初待传输的粒子态,从而,成功实现该隐形传输。文章还以三粒子的传输为例作了详细介绍。     

Teleportation of N-Particle Entangled GHZ State via Entanglement Swapping

In this scheme, N non-maximally entangled particle pairs are used as quantum channel to teleport an unknown N-particle entangled GHZ state via entanglement swapping. In order to realize this teleportation, the sender Alice operates Bell-state measurement on particles belonging to herself. Then she informs the results to the receiver Bob through classical communication. According to the results, Bob operates corresponding transformation to reconstruct the initial state. The advantage of this scheme is that it needs only one common unitary matrix for Alice＇s different results, which has a more general meaning. As a special case, teleporting an unknown three-particle entangled GHZ state is proposed.     

Probabilistic Teleportation of an Arbitrary Two-Particle State and Its Quantum Circuits

Two simple schemes for probabilistic teleportation of an arbitrary unknown two-particle state using a non-maximally entangled EPR pair and a non-maximally entangled GHZ state as quantum channels are proposed. After receiving Alice's Bell state measurement results, Bob performs a collective unitary transformation on his inherent particles without introducing the auxiliary qubit. The original state can be probabilistically teleported. Meanwhile, quantum circuits for realization of successful teleportation are also presented.     

Teleportation of n-Particle State via n Pairs of EPR Channels

The teleportation of an arbitrary n-particle state (n ≥ 1) is proposed if n pairs of identical EPR states are utilized as quantum channels. Independent Bell state measurements are performed for joint measurement. By using a special Latin square of order 2n(n ≥ 1), explicit expressions of outcomes after the Bell state measurements by Alice (sender) and the corresponding unitary transformations by Bob (receiver) can be derived. It is shown that the teleportation of n-particle state can be implemented by a series of single-qubit teleportation.     

Quantum Teleportation of One-to-Many Using （n ＋ 1）-Particle Entanglement

In this paper, quantum teleportatlon of one-to-many using （n ＋1）-particle entanglement is presented. If the sender （Alice） wants to transmit an unknown quantum state to a distant receiver （Bob）, similar to the previous schemes, Alice performs Bell-state measurement on particles belonging to herself and informs the receiver the results through the classical channel. After that, it needs to perform the Hadamard operation on the other （n - 1） particles and measure them as well. With the aid of the measurement results, Bob can operate a corresponding unitary transformation on his particle to reconstruct the original state. Of course, the reconstruction may realize at either location of n, but it cannot realize at all locations at the same time.     

Teleportations of Mixed States and Multipartite Quantum States

In this paper, we propose a protocol to deterministically teleport an unknown mixed state of qubit by utilizing a maximally bipartite entangled state of qubits as quantum channel. Ira non-maximally entangled bipartite pure state is employed as quantum channel, the unknown mixed quantum state of qubit can be teleported with 1 -√ 1- C^2 probability, where C is the concurrence of the quantum channel. The protocol can also be generalized to teleport a mixed state of qudit or a multipartite mixed state. More important purpose is that, on the basis of the protocol, the teleportation of an arbitrary multipartite （pure or mixed） quantum state can be decomposed into the teleportation of each subsystem by employing separate entangled states as quantum channels. In the case of deterministic teleportation, Bob only needs to perform unitary transformations on his single particles in order to recover the initial teleported multipartite quantum state.     

Probabilistic teleportation of an arbitrary GHZ-class state with a pure entangled two-particle quantum channel and its application in quantum state sharing

This paper presents a scheme for probabilistic teleportation of an arbitrary GHZ-class state with a pure entangled two-particle quantum channel. The sender Alice first teleports the coefficients of the unknown state to the receiver Bob, and then Bob reconstructs the state with an auxiliary particle and some unitary operations if the teleportation succeeds. This scheme has the advantage of transmitting much less particles for teleporting an arbitrary GHZ-class state than others. Moreover, it discusses the application of this scheme in quantum state sharing.     

A new representation and probabilistic teleportation of an arbitrary and unknown N-particle state

A new representation of an arbitrary and unknown N-particle state is presented at first. As an application, a scheme for teleporting an arbitrary and unknown N-particle state is proposed when N pairs of two-particle non- maximally entangled states are utilized as quantum channels. After Alice （sender） makes Bell-state measurement on her particles, Bob （recipient） introduces an auxiliary particle and carries out appropriate unitary transformation on his particle and the auxiliary particle depending on classical information from Alice. Then, von Neumann measurement that confirms whether the teleportation succeeds or not is performed by Bob on the auxiliary particle. In order to complete the teleportation, another N-1 times operations need to be performed which are similar to the above ones. It can be successfully realized with a certain probability which is determined by the product of the smaller coefficients of non-maximally entangled pairs. All possible unitary transformations are given in detail.