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.     

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.     

基于纠缠交换和团簇态实现二粒子任意态的可控隐形传态

提出一个对二粒子任意态的可控隐形传态方案,利用四粒子团簇态作为量子信道,用EPR态实现控制.首先,发送者向控制者提出申请,控制者再对其拥有的2个粒子做Bell基测量,并把结果通知发送者,实现纠缠交换.然后,发送者对自己手中的四个粒子做适当的幺正变换,接着进行纽曼测量,并把结果通知接受者.接受者根据发送者的测量结果,对自己拥有的粒子做适当的幺正变换,就可以重建发送者的二粒子任意态.方案成功的概率为100%.     

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.     

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.     

Controlled Teleportation of an Arbitrary Two-Particle Pure or Mixed State by Using a Five-Qubit Cluster State

A new scheme for controlled teleportation of an arbitrary two-particle pure or mixed state with the help of a five-qubit cluster state is proposed in detail. In this scheme, a five-particle cluster state is shared by a sender, a controller and a receiver. At first, the sender performs a four-qubit von-Neumann measurement on the qubits at hand, and the controller performs a Hadamard measurement on his qubit. Then the receiver can reconstruct the arbitrary two-particle pure or mixed state by performing some appropriate unitary transformations on his particles after he knows the measure results of the sender and the controller. This controlled teleportation scheme is deterministic.     

Two Quantum Proxy Blind Signature Schemes Based on Controlled Quantum Teleportation

We present a scheme for teleporting an unknown, two-particle entangled state with a message from a sender (Alice) to a receiver (Bob) via a six-particle entangled channel. We also present another scheme for teleporting an unknown one-particle entangled state with a message transmitted in a two-way form between the same sender and receiver via a five-qubit cluster state. One-way hash functions, Bell-state measurements, and unitary operations are adopted in these two schemes. Our schemes use the physical characteristics of quantum mechanics to implement delegation, signature, and verification processes. Moreover, a quantum key distribution protocol and a one-time pad are adopted in these schemes.     

Optimal conclusive teleportation of a d-dimensional two-particle unknown quantum state

A conclusive teleportation protocol of a d-dimensional two-particle unknown quantum state using three d- dimensional particles in an arbitrary pure state is proposed. A sender teleports the unknown state conclusively to a receiver by using the positive operator valued measure（POVM） and introducing an ancillary qudit to perform the generalized Bell basis measurement, We calculate the optimal teleportation fidelity. We also discuss and analyse the reason why the information on the teleported state is lost in the course of the protocol,     

一种两粒子任意态的概率传送方案

提出一种采用两组一般三粒子W态作为信道的传送两粒子任意态的方案.在此方案中,在发送者作Bell基测量后,接受者需要采用幺正变换和冯·诺依曼测量来实现传送方案.接受者可以选择在不同的粒子上恢复未知态,选择适当的幺正变换可使传态成功概率相等.     

Several teleportation schemes of an arbitrary unknown multi-particle state via different quantum channels

We first provide four new schemes for two-party quantum teleportation of an arbitrary unknown multi-particle state by using three-, four-, and five-particle states as the quantum channel, respectively. The successful probability and fidelity of the four schemes reach 1. In the first two schemes, the receiver can only apply one of the unitary transformations to reconstruct the original state, making it easier for these two schemes to be directly realized. In the third and fourth schemes, the sender can preform Bell-state measurements instead of multipartite entanglement measurements of the existing similar schemes, which makes real experiments more suitable. It is found that the last three schemes may become tripartite controlled teleportation schemes of teleporting an arbitrary multi-particle state after a simple modification. Finally, we present a new scheme for three-party sharing an arbitrary unknown multi-particle state. In this scheme, the sender first shares three three-particle GHZ states with two agents. After setting up the secure quantum channel, an arbitrary unknown multi-particle state can be perfectly teleported if the sender performs three Bell-state measurements, and either of two receivers operates an appropriate unitary transformation to obtain the original state with the help of other receiver's three single-particle measurements. The successful probability and fidelity of this scheme also reach 1. It is demonstrated that this scheme can be generalized easily to the case of sharing an arbitrary unknown multi-particle state among several agents.     

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.     

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.     

Scheme for Cloning an Unknown Entangled State with Assistance via Non-maximally Entangled Cluster States

We propose a scheme for cloning unknown two-particle entangled state and its orthogonal complement state with assistance from a state preparer. Two stages were included in this scheme. The first stage requires usual teleportation by using a one-dimensional non-maximally four-particle cluster state as quantum channel, after Alice’s (the state sender) Bell measurement, Bob (the state receiver) can get the original state with certain probability. In the second stage, after having received Victor’s (the state preparer) classical message, the perfect copies and complement copies of an unknown state can be produced in Alice’s place, the probability of Alice to get the original state or its orthogonal complement state are calculated. Assisted cloning of an arbitrary unknown two-particle entangled state is discussed in the latter scheme.     

Multiparty-Controlled Remote Preparation of Two-Particle State

We propose a scheme for multiparty-controlled remote preparation of the two-particle state by using two non-maximally Greenberger-Horne-Zeilinger states as quantum channel. Our scheme consists of one sender and n remote receivers. It will be shown that the sender can help either one of the n receivers to remotely preparation the original state with the appropriate probability, and the sender Alice's two-particle projective measurement and the controllers' single-particle product measurements are needed. We also obtained the probability of the successful remote state preparation.     

Probabilistic Teleportation of an Arbitrary Three-Level Two-Particle State and Classical Communication Cost

We propose a scheme to probabilistically teleport an unknown arbitrary three-level two-particle state by using two partial entangled two-particle states of three-level as the quantum channel. The classical communication cost required in the ideal probabilistic teleportation process is also calculated. This scheme can be directly generalized to teleport an unknown and arbitrary three-level K-particle state by using K partial entangled two-particle states of three-level as the quantum channel.     

Probabilistic Teleportation of an Arbitrary Three-Level Two-Particle State and Classical Communication Cost

We propose a scheme to probabilistically teleport an unknown arbitrary three-level two-particle state by using two partial entangled two-particle states of three-level as the quantum channel. The classical communication cost required in the ideal probabilistic teleportation process is also calculated. This scheme can be directly generalized to teleport an unknown and arbitrary three-level K-particle state by using K partial entangled two-particle states of three-level as the quantum channel.     

Teleportation of Two-Particle Entangled State via Cluster State

In this paper,two schemes for teleporting an unknown two-particle entangled state from the sender (Alice)to the receiver (Bob) via a four-particle entangled cluster state are proposed.In these two schemes,the unknown twoparticle entangled state can be teleported perfectly.The successful probabilities and fidelities of the schemes can reach unity.     

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.     

Quantum state sharing of an arbitrary m-qudit state with two-qudit entanglements and generalized Bell-state measurements

A scheme for quantum state sharing of an arbitrary m-qudit state is proposed with two-qudit entanglements and generalized Bell-state (GBS) measurements. In this scheme, the sender Alice should perform m two-particle GBS measurements on her 2m qudits, and the controllers also take GBS measurements on their qudits and transfer their quantum information to the receiver with entanglement swapping if the agents cooperate. We discuss two topological structures for this quantum state sharing scheme, a dispersive one and a circular one. The former is better at the aspect of security than the latter as it requires the number of the agents who should cooperate for recovering the quantum secret larger than the other one.