Probabilistic teleportation of an unknown N-atom state using a two-atom nonmaximally entangled state in cavity QED

We present a scheme for realizing probabilistic teleportation of an unknown N-atom state via cavity QED. This scheme requires only a nonmaximally entangled pair to be used as a quantum channel, so the requirement of entanglement is reduced. In addition, our scheme does not involve the Bell-state measurement and is insensitive to the cavity decay, which is important from the experimental point of view. If the quantum channel is a two-atom maximally entangled state, teleportation of an unknown N-atom state can be realized by a simpler scheme via cavity QED.     

Teleportation of a multiqubit state by an entangled qudit channel

We investigate the problem of teleportation of an M-qubit state by using an entangled qudit pair as a quan-tum channel and show that the teleportation of a multiparticle state can correspond to the teleportation of a multi-dimensional state. We also introduce a quantum-state converter composed of beamsplitter arrays, on/off-detectors and cross-Kerr couplers and demonstrate that the state conversion from an M-qubit to an N-dimensional qudit and vice versa can be implemented with this converter, where N = 2^M. Based on this, an experimentally feasible scheme for the teleportation of an M-qubit via an entangled N-level qudit pair channel is proposed.     

Probabilistic Teleportation of an Unknown Two-Particle State with a Four-Particle Pure Entangled State and Positive Operator Valued Measure

We propose a scheme for probabilistic teleportation of an unknown two-particle state with a four-particle pure entangled state and positive operator valued measure （POVM）. In this scheme the teleportation of an unknown two-particle state can be realized with certain probability by performing two Bell state measurements, a proper POVM and a unitary transformation.     

Teleportation of Entangled States through Divorce of Entangled Pair Mediated by a Weak Coherent Field in a High-Q Cavity

We propose a scheme to partially teleport an unknown entangled atomic state. A high-Q cavity, supporting one mode of a weak coherent state, is needed to accomplish this process. By partial teleportation we mean that teleportation will occur by changing one of the partners of the entangled state to be teleported. The entangled state to be teleported is composed by one pair of particles, we called this surprising characteristic of maintaining the entanglement, even when one of the particle of the entangled pair being teleported is changed, of divorce of entangled states.     

Quantum Teleportation of a Three—Particle Entangled State

We present a scheme for teleporting a three-particle entangled state to three remote particles.In this scheme,three pairs of pure nonmaximally entangled states are considered as quantum channels.It is found that by means of optimal discrimination between two nonorthogonal quantum states,probabilistic teleportation of the three-particle entangled state can be achieved.     

Schemes for Teleportation of an Unknown Single-Qubit Quantum State by Using an Arbitrary High-Dimensional Entangled State

We propose a scheme to teleport an unknown single-qubit state by using a high-dimensional entangled state as the quantum channel. As a special case, a scheme for teleportation of an unknown single-qubit state via three-dimensional entangled state is investigated in detail. Also, this scheme can be directly generalized to an unknown f-dimensional state by using a d-dimensional entangled state （d〉f） as the quantum channel.     

A New Scheme for Probabilistic Teleportation and Its Potential Applications

We propose a novel scheme to probabilistically teleport an unknown two-level quantum state when the information of the partially entangled state is only available for the sender. This is in contrast with the fact that the receiver must know the non-maximally entangled state in previous typical schemes for the teleportation. Additionally, we illustrate two potential applications of the novel scheme for probabilistic teleportation from a sender to a receiver with the help of an assistant, who plays distinct roles under different communication conditions, and our results show that the novel proposal could enlarge the applied range of probabilistic teleportation.     

Distributed wireless quantum communication networks with partially entangled pairs

Wireless quantum communication networks transfer quantum state by teleportation. Existing research focuses on maximal entangled pairs. In this paper, we analyse the distributed wireless quantum communication networks with partially entangled pairs. A quantum routing scheme with multi-hop teleportation is proposed. With the proposed scheme, is not necessary for the quantum path to be consistent with the classical path. The quantum path and its associated classical path are established in a distributed way. Direct multi-hop teleportation is conducted on the selected path to transfer a quantum state from the source to the destination. Based on the feature of multi-hop teleportation using partially entangled pairs, if the node number of the quantum path is even, the destination node will add another teleportation at itself. We simulated the performance of distributed wireless quantum communication networks with a partially entangled state. The probability of transferring the quantum state successfully is statistically analyzed. Our work shows that multi-hop teleportation on distributed wireless quantum networks with partially entangled pairs is feasible.     

Efficient scheme for teleportation of an unknown N-atom state via a two-atom entangled state without the Bell-state measurement in cavity QED

We propose a scheme for teleportation of an unknown N-atom state using a two-atom entangled state within a cavity QED and show the feasibility in experiment. Our scheme does not involve the Bell-state measurement and is insensitive to the cavity decay, which is important from the experimental point of view. Another feature of the scheme is that teleporting a N-atom state just requires a small amount of entanglement （i,e. a two-atom entangled state） and less classical bits （two bits）.     

Teleportation of N-particlstate via entanglemente entangled W swapping

A scheme for teleporting an unknown N-particle entangled W state is proposed via entanglement swapping. In this scheme, N maximally entangled particle pairs are used as quantum channel. As a special case, the teleportation of an unknown four-particle entangled W state is studied.     

三粒子纠缠Ｗ态的隐形传态

提出利用三个二粒子纠缠态作为量子信道，实现三粒子纠缠Ｗ态的隐形传态的方案.首先考察量子信道是最大纠缠态的情形，然后进一步考察量子信道是非最大纠缠态的情形.发现在量子信道为非最大纠缠态时，通过引进一个辅助粒子，并构造一个幺正变换矩阵，即可以一定的概率完成三粒子纠缠Ｗ态的隐形传态. 关键词： 隐形传态 三粒子纠缠 纠缠Ｗ态 非最大纠缠量子信道     

多粒子纠缠W态的多控制隐形传输和保真度的研究

讨论了三粒子纠缠W态的三人控制的隐形传输和控制方中有一个人、两个人和三个人不合作时接收方获得发送方的量子态的保真度,接着研究了多粒子纠缠W态的多控制隐形传输的方案,并且讨论了当有X个控制方不合作时接收方获得发送方的量子态的保真度.     

三粒子纠缠W态隐形传态的正交完备基展开与算符变换

先是对利用单个两粒子及单个三粒子纠缠态作为量子信道实现三粒子纠缠W态的隐形传态方案进行讨论.然后由波函数的叠加原理与算符变换出发,将体系的总量子量按照Bell基展开实现量子隐形传态,给出了变换算符与实际操作算符之间的联系.进一步验证出变换算符可逆是成功实现三粒子纠缠W态隐形传态的必要条件的结论. 关键词： 三粒子纠缠W态 Bell基展开 变换算符 隐形传态     

Preparation of partially entangled W state and deterministic multi-controlled teleportation

We give a protocol to prepare special partially entangled multi-atom W states. Besides, a scheme for deterministic and multi-controlled teleportation of an arbitrary unknown two-level two-atom state via partially entangled W states is proposed.     

四粒子纠缠的一般W态的退纠缠和W态的概率隐形传态

我们推广地得到了到四粒子纠缠的一般W态,给出了一般W态的不同退纠缠的条件,得到了一个新的二粒子的一般W态,并得到对于四粒子纠缠的一般W态而言,其系数α1,α2和α3从一个直到全部为零时,这一般的|ΨW〉依次有一个粒子,二个粒子和最后全部粒子退出纠缠。还给出了一个利用四个二粒子纠缠态作为量子信道来传送四粒子纠缠W态的方案,并且进一步给出了当量子信道为非最大纠缠态时,四粒子纠缠的一般W态的隐形传态的一个方案,同时通过构造一个5×5对角投影变换矩阵,解决了使用一般纠缠量子信道并不再引入辅助态时,态畸变的恢复问题.并且这里的对角投影变换UM也与以往文献中的不同,而且比过去文献的讨论更直接.因本文的研究是一般性的,本文关于对角的投影变换矩阵UM的变换方法等可以直接推广到任意一般纠缠信道的一般纠缠态的概率隐形传态。     

Multi-hop teleportation based on W state and EPR pairs

Multi-hop teleportation has significant value due to long-distance delivery of quantum information. Many studies about multi-hop teleportation are based on Bell pairs, partially entangled pairs or W state. The possibility of multi-hop teleportation constituted by partially entangled pairs relates to the number of nodes. The possibility of multi-hop teleportation constituted by double W states is (4/9)~n after n-hop teleportation. In this paper, a multi-hop teleportation scheme based on W state and EPR pairs is presented and proved. The successful possibility of quantum information transmitted hop by hop through intermediate nodes is deduced. The possibility of successful transmission is (2/3)~n after n-hop teleportation.     

Teleportation with Tripartite Entangled State via Thermal Cavity

Teleportation schemes with a tripartite entangled state in cavity QED are investigated. The schemes do not need Bell state measurements and the successful probabilities reach optimality. In addition, the schemes are insensitive to both the cavity decay and the thermal field. We first consider two teleportation schemes via a tripartite GHZ state. The first one is a controlled one for an unknown single-qubit state. The second scheme is teleportation of unknown two-atom entangled state. Then we consider teleporting of single-qubit arbitrary state via a tripartite W state.     

Teleportation with Tripartite Entangled State via Thermal Cavity

Teleportation schemes with a tripartite entangled state in cavity QED are investigated. The schemes do not need Bell state measurements and the successful probabilities reach optimality. In addition, the schemes are insensitive to both the cavity decay and the thermal field. We first consider two teleportation schemes via a tripartite GHZ state.The first one is a controlled one for an unknown single-qubit state. The second scheme is teleportation of unknown two-atom entangled state. Then we consider teleporting of single-qubit arbitrary state via a tripartite W state.     

利用cluster态隐形传送任意三原子W态

提出一个隐形传送任意三原子纠缠W态的方案,在此方案中,选用由四个全同的二能级原子组成的cluster态作为量子信道.研究表明,接收者基于发送者的经典信息,借助于一个附加原子,实行联合幺正变换以及单原子幺正变换,可实现三原子W态的隐形传送.该方案不受外界热场和腔场耗散的影响,不需要贝尔态测量,成功实现传送的几率为1.