用非最大纠缠信道对任意二粒子纠缠态的量子秘密分享

提出一个对任意二粒子纠缠态在N者之间的量子秘密分享方案,该方案利用非最大纠缠Einstein-Podolsky-Rosen(EPR)对作为量子信道,利用广义的贝尔基进行测量.接收者通过引入辅助粒子,并对其做选择性测量,就会概率性地得到最初的量子态. 关键词： 非最大纠缠的Einstein-Podolsky-Rosen(EPR)对 广义的贝尔测量     

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.     

Controlled Teleportation of an Arbitrary Two-Particle State by One EPR Pair and Cluster State

A scheme for controlled teleportation of an arbitrary two-particle state using a maximally entangled EPR pair and a cluster state as the quantum channel is proposed. After receiving Alice's Bell state measurement results, the controller performs a joint measurement on his particles under a non-maximally entangled Bell-basis.The receiver needs to introduce an auxiliary qubit, and performs aseries of appropriate unitary transformations on his particles.
The original state can be teleported successfully with theprobability 2cos²θ.     

Probabilistic Controlled Teleportation of Two-Particle Entangled State via the Optimal Quantum State

Via a non-maximally entangled state as the optimal quantum channel, we discuss the probabilistic controlled teleportation of two-particle anti-correlation entangled state. We first defines four-particle special “anti-correlation GHZ state” as the quantum channel, then the sender and the controller do a series of measurements. According to their measurements, the receiver perform an appropriate unitary transformation and measurement on the auxiliary particle, then he can get the quantum state he wants. Moreover, We present the successful probability of the above controlled teleportation.     

Teleportation of an unknown bipartite state via non-maximally entangled two-particle state

In this paper a new scheme for teleporting an unknown entangled state of two particles is proposed. To weaken the requirement for the quantum channel, without loss of generality, two communicators only share a non-maximally entangled two-particle state. Teleportation can be probabilistically realized if sender performs Bell-state measurements and Hadamard transformation and receiver introduces two auxiliary particles, operates C-not operation, single-qubit measurements and appropriate unitary transformations. The probability of successful teleportation is determined by the smaller one among the coefficients' absolute values of the quantum channel.     

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.     

Teleportation of an arbitrary three—particle state

We propose two schemes for teleporting an arbitrary three-particle state.In the first scheme,a two-particle state and a three-particle entangled state (both non-maximally entangled states)are used as quantum channels,while in the second scheme,three non-mnaximally entangled particle pairs are employed as quantum channels.We show that teleportation can be successfully realized with certain probability if a receiver adopts some appropriate unitary transformations.Their success probabilities and the classical communication costs are different.     

Hierarchical and probabilistic quantum state sharing via a non-maximally entangled |χ〉 state

A scheme that probabilistically realizes hierarchical quantum state sharing of an arbitrary unknown qubit state with a four-qubit non-maximally entangled |χ state is presented in this paper. In the scheme, the sender Alice distributes a quantum secret with a Bell-state measurement and publishes her measurement outcomes via a classical channel to three agents who are divided into two grades. One agent is in the upper grade, while the other two agents are in the lower grade. Then by introducing an ancillary qubit, the agent of the upper grade only needs the assistance of any one of the other two agents for probabilistically obtaining the secret, while an agent of the lower grade needs the help of both the other two agents by using a controlled-NOT operation and a proper positive operator-valued measurement instead of the usual projective measurement. In other words, the agents of two different grades have different authorities to reconstruct Alice’s secret in a probabilistic manner. The scheme can also be modified to implement the threshold-controlled teleportation.     

Controlled Secure Quantum Dialogue Using a Pure Entangled GHZ States

We present a controlled secure quantum dialogue protocol using a non-maximally （pure） entangled Greenberger-Horne-Zeibinger （GHZ） states at first, and then discuss the requirements for a real quantum dialogue. We show that the authorized two users can exchange their secret messages after purifying the non-maximally entangled GHZ states quantum channel unconditionally securely and simultaneously under the control of a third party.     

Controlled Secure Quantum Communication Using Pure Entangled W Class States

We present a controlled secure quantum communication protocol using non-maximally （pure） entangled W states first, and then discuss the basic requirements for a real quantum communication. We show that the authorized two users can exchange their secret messages with the help of the controller after purifying the non-maximally entangled states quantum channel unconditionally securely and simultaneously. Our quantum communication protocol seems even more feasible within present technologies.     

Generalized Multiparty Quantum Single-Qutrit-State Sharing

We present a three-party quantum single-qutrit-state sharing scheme with a non-maximally entangled three-qutrit state as the quantum channel. In the scheme, the sender’s secret quantum information (i.e., the single-qutrit state) is split in such a way that it can be probabilistically reconstructed through introducing an auxiliary qutrit and performing appropriate operations provided that the receivers both collaborate together. We work out the success probability and reveal the relation between the probability and the parameters characterizing the quantum channel. After this, we then briefly introduce the generalization of the three-party scheme to a more-party one.     

通过cluster态实现两粒子纠缠态的量子几率隐形传态

提出通过一个四粒子cluster非最大纠缠态作为量子信道来实现一未知两粒子纠缠态的量子几率隐形传态方案。在此方案中,纠缠态可以实现一定的几率传输,此几率由cluster态中绝对值较小的两个系数决定。如果我们用cluster最大纠缠态作为量子信道,此时几率隐形传态就成了一般的隐形传态,即成功传输的几率为100%。     

Probabilistic teleportation of an arbitrary three-particle state via a partial entangled four-particle state and a partial entangled pair

We present a scheme to probabilistically teleport an arbitrary and unknown three-particle state via a two-particle non-maximally entangled state and a four-particle non-maximally entangled state as the quantum channel. With the help of Bell-state measurements, an arbitrary three-particle state can be perfectly teleported if a receiver introduces a collective unitary transformation. All kinds of unitary transformations are given in greater detail. This scheme can be generalized to the teleportation of an arbitrary and unknown multiparticle state.     

Generalized quantum state sharing of the arbitrary two particles state

This paper has proposed a generalized quantum state sharing protocol of an arbitrary two-particle state using non-maximally GHZ states and generalized Bell state measurement.The sender Alice performs two-particle generalized Bell state measurements on her two particles in the state sharing process and the controller takes measurements on his particles and transfers the quantum information to the receiver with entanglement swapping by the cooperation of the other agents.It is found that the use of nonmaximally entangled state in quantum state sharing has enabled the secure sharing of the quantum state.     

Three-party quantum secret sharing of secure direct communication based on x-type entangled states

Based on x-type entangled states and the two-step protocol [Deng F G, Long G L and Liu X S 2003 Phys. Rev. A 68 042317], a quantum secret sharing protocol of secure direct communication based on x-type entangled states ｜X00〉3214 is proposed. Using some interesting entanglement properties of this state, the agent entirety can directly obtain the secret message from the message sender only if they collaborate together. The security of the scheme is also discussed.     

Probabilistic Remote Preparation of a Three-Particle Entangled State via Two Different Non-maximally Entangled Channels

We present two schemes for preparing remotely a three-particle entangled state by two different quantum channels. In the first scheme, two partial three-particle entangled states are used as the quantum channels, while in the second scheme, three two-particle non-maximally entangled states are employed as the quantum channels. It is shown that the remote state preparation can be successfully realized with certain probability, for both two schemes, if a sender performs some projective measurements and a receiver adopts some appropriate unitary transformations. It is shown also that the successful probabilities of these two schemes are different.     

Probabilistic Remote Preparation of a Three-Particle Entangled State via Two Different Non-maximally Entangled Channels

We present two schemes for preparing remotely a three-particle entangled state by two different quantum channels. In the first scheme, two partial three-particle entangled states are used as the quantum channels, while in the second scheme, three two-particle non-maximally entangled states are employed as the quantum channels. It is shown that the remote state preparation can be successfully realized with certain probability, for both two schemes, if a sender performs some projective measurements and a receiver adopts some appropriate unitary transformations. It is shown also that the successful probabilities of these two schemes are different.     

利用三粒子部分纠缠GHZ 态和二粒子纠缠态概率隐形传送任意二粒子态

我们提出了利用三粒子非最大纠缠GHZ态和二粒子非最大纠缠态从一个发送者概率隐形传送任意未知二粒子态至两个接收者中的一个的方案。发送者进行两次Bell-state 测量，接收者以另一个可能的接收者进行的Hadamard操作和投影测量的结果为条件引入两个适当的幺正变换就可以概率隐形传送任意未知二粒子态。     

Probabilistic teleportation of an arbitrary three-particle state

A scheme for teleporting an arbitrary and unknown three-particle state from a sender to either one of two receivers is proposed. The quantum channel is composed of a two-particle non-maximally entangled state and two three-particle non-maximally entangled W states. An arbitrary three-particle state can be perfectly teleported probabilistically if the sender performs three generalized Bell-state measurements and sends to the two receivers the classical result of these measurements, and either one of the two receivers adopts an appropriate unitary transformation conditioned on the suitable measurement outcomes of the other receiver. All kinds of unitary transformations are given in detail.     

Schemes for Probabilistic Teleportation of an Unknown Three-Particle Three-Level Entangled State

In this paper, two schemes for teleporting an unknown three-particle three-level entangled state are proposed. In the first scheme, two partial three-particle three-level entangled states are used as the quantum channels, while in the second scheme, three two-particle three-level non-maximally entangled states are employed as quantum channels. It is shown that the teleportation can be successfully realized with certain probability, for both two schemes, if a receiver adopts some appropriate unitary transformations. It is shown also that the successful probabilities of these two schemes are different.