Remote preparation of a Greenberger--Horne--Zeilinger state via a two-particle entangled state

We present two schemes for realizing the remote preparation of a Greenberger--Horne--Zeilinger (GHZ) state. The first scheme is to remotely prepare a general N-particle GHZ state with two steps. One is to prepare a qubit state by using finite classical bits from sender to receiver via a two-particle entangled state, and the other is that the receiver introduces N - 1 additional particles and performs N - 1 controlled-not (C-Not) operations. The second scheme is to remotely prepare an N-atom GHZ state via a two-atom entangled state in cavity quantum electrodynamics (QED). The two schemes require only a two-particle entangled state used as a quantum channel, so we reduce the requirement for entanglement.     

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.     

Deterministic secure quantum communication using four-particle genuine entangled state and entanglement swapping

A deterministic secure quantum communication scheme using entanglement swapping is proposed. The sender prepares four-particle genuine entangled states and sends two particles in each state to the receiver and remains the rest particles. If the quantum channel is secure, they begin to communicate. After their four-particle projective measurements, the receiver can obtain the secret information according to his measurement outcomes and classical information from the sender. Using entanglement swapping, there are no particles carrying secret information to be transmitted.     

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.     

Controlled Remote Preparing of an Arbitrary 2-Qudit State with Two-Particle Entanglements and Positive Operator-Valued Measure

We present a scheme for symmetric controlled remote preparation of an arbitrary 2-qudit state form a sender to either of the two receivers via positive operator-valued measurement and pure entangled two-particle states. The first sender transforms the quantum channel shared by all the agents via POVM according to her knowledge of prepared state. All the senders perform singIe- or two-particle projective measurements on their entangled particles and the receiver can probabilisticaly reconstruct the original state on her entangled particles via unitary transformation and auxiliary qubit. The scheme is optimal as the probability which the receiver prepares the original state equals to the entanglement of the quantum channel. Moreover, it is more convenience in application than others as it requires only two-particle entanglements for preparing an arbitrary two-qudit state.     

Deterministic hierarchical joint remote state preparation with six-particle partially entangled state

In this paper, we present a novel scheme for hierarchical joint remote state preparation(HJRSP) in a deterministic manner, where two senders can jointly and remotely prepare an arbitrary single-qubit at three receivers' port. A six-particle partially entangled state is pre-shared as the quantum channel. There is a hierarchy among the receivers concerning their powers to reconstruct the target state. Due to various unitary operations and projective measurements, the unit success probability can always be achieved irrespective of the parameters of the pre-shared partially entangled state.     

基于(2m+1)粒子纠缠态的任意m粒子态量子可控离物传态(英文)

提出了一个基于高维2m+1粒子纠缠态的任意m粒子态量子可控离物传态方案,发送方Alice对需传送的未知态量子系统和手中的纠缠粒子执行m个广义Bell基测量,控制方执行广义X基测量,依据预先共享量子纠缠态非定域相关性,接收方对手中的粒子执行相应的幺正操作就可以重建原来未知量子态.与其他方案相比,方案减少了任意高维多粒子态可控离物传送所需传送粒子数.我们进一步讨论了基于纯纠缠信道的概率量子可控离物传态方案,通过与发送方和控制方合作,接收方只需对手中的纠缠粒子和引入的附加粒子执行联合幺正演化和投影测量,就可以在他的粒子上概率的重建原来的未知量子态,最后,方案计算讨论了基于纯纠缠态量子可控离物传态成功概率与信道纠缠度之间的关系.     

Efficient Joint Remote Preparation of an Arbitrary m-qudit State with Partially Entangled States

We present an efficient scheme for multiparty joint remote preparation of an arbitrary m-qudit state by using partially entangled states as the quantum channel. One of the senders first performs a collective unitary transformation on his entangled particles and the auxiliary qubit, and then he performs a Z-basis measurement on the auxiliary qubit for transforming the partially entangled quantum channel into the two types of multi-particle entangled states. In the first case, the quantum channel shared by all the senders and the receiver is the target channel. In the second case, the quantum channel transforms into another partially entangled state which is the resource for the quantum channel transformation in the next round. Compared with other protocols, our scheme has advantage of having high success probability for joint remote preparation of an arbitrary m-qudit state via partially entangled states.     

Quantum state sharing of an arbitrary qudit state by using nonmaximally generalized GHZ state

We present a scheme for quantum state sharing of an arbitrary qudit state by using nonmaximally entangled generalized Greenberger-Horne-Zeilinger （GHZ） states as the quantum channel and generalized Bell-basis states as the joint measurement basis. We show that the probability of successful sharing an unknown qudit state depends on the joint measurements chosen by Alice. We also give an expression for the maximally probability of this scheme.     

Efficient multi-party quantum state sharing of an arbitrary two-qubit state

We present an efficient scheme for sharing an arbitrary two-qubit quantum state with n agents. In this scheme, the sender Alice first prepares an n + 2-particle GHZ state and introduces a Controlled-Not (CNOT) gate operation. Then, she utilizes the n + 2-particle entangled state as the quantum resource. After setting up the quantum channel, she performs one Bell-state measurement and another single-particle measurement, rather than two Bell-state measurements. In addition, except that the designated recover of the quantum secret just keeps two particles, almost all agents only hold one particle in their hands respectively, and thus they only need to perform a single-particle measurement on the respective particle with the basis X. Compared with other schemes based on entanglement swapping, our scheme needs less qubits as the quantum resources and exchanges less classical information, and thus obtains higher communication efficiency.     

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。     

Teleportation of the three-level three-particle entangled state and classical communication cost

We propose a scheme to probabilistically teleport an unknown three-level three-particle entangled state. The quantum channel is composed of a partial entangled three-level two-particle state and a partial entangled three-level three-particle state. We calculate the successful total probability and the classical communication cost required in the ideal probabilistic teleportation process, respectively. It is shown that an unknown three-level three-particle entangled state can be teleported using fewer entangled particles and lesser classical communication cost than Bennett et al.’s original protocol.     

基于GHZ纠缠态实现纯EPR对的双向量子隐形传态

提出了一种基于Greenberger-Horne-Zeilinger(GHZ)纠缠态进行纯EPR对双向隐形传态的方案.通过使用纠缠交换技术,通信双方Alice和Bob共享两对三粒子GHZ纠缠态来构建量子信道.方案中通过使用受控非门操作,单量子位测量以及适当的幺正操作,通信双方可以同时发送一个纯EPR对给对方.故相比仅可以传送单一量子态的方案更经济.     

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。     

Quantum teleportation of an entangled 2-photon polarization state with preparing determinately two Bell states based on cross-Kerr nonlinearity

A scheme, in which cross-Kerr nonlinearity is used for the Bell-state measurements and preparation of the resource of entanglement, is proposed for teleporting an entangled 2-photon state by using two polarization-photon Bell states as quantum channel based on cross-Kerr nonlinearity combined with linear optics elements such as polarization beam splitters and half wave plates. Teleportation of the entangled 2-photon polarization state can realized with certainty in principle.     

Schemes for Splitting Quantum Information with Four-Particle Genuine Entangled States

We propose two schemes for splitting single- and two-qubit states by using four-particle genuine entangled state as the quantum channel. After the sender performs Bell-basis （or three-partite GHZ- basis） measurements on her particles, and the cooperators operate single-particle measurements on their particles, the state receiver can reconstruct the original state of the sender by applying the appropriate unitary operation. In particular, in the scheme for splitting two-qubit state, the receiver needs to introduce an auxiliary particle and carries out a C-NOT operation.     

二粒子部分纠缠未知态的量子受控传递

提出了二粒子部分纠缠态的量子隐形传递控制方案.在该方案中，以四个二能级粒子GHZ态作为量子通道，把量子通道中的一个粒子作为控制粒子.在传递者和控制者进行一系列的量子操作和测量之后，根据他们的测量结果，接收者再进行适当的变换就能得到待传递粒子的量子态.     

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.     

Probabilistic Teleportation of Three-Atom State via Five-Atom Cluster State

A scheme for probabilistic teleportation of an unknown three-atom entangled state via a five-atom non-maximally entangled cluster state as quantum channel is proposed. In this scheme, the sender performs two Bell state and a single-atom measurements on the atoms, the receiver can reconstruct the original state with a certain probability by introducing an auxiliary atom and operating appropriate unitary transformations and controlled-not (C-not) operations according to the sender Alice's measurement results. As a result, the probability of successful teleportation is determined by the smallest two of the coefficients'absolute values of the cluster state. The considerable advantage of our scheme is that we employ a non-maximally entangled cluster state as quantum channel in the scheme, which can greatly reduce the amount of entanglement resources and need less classical bits. If we employ a maximally entangled cluster state as quantum channel, the probabilistic teleportation scheme becomes usual teleportation, the successful probability being 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.