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.     

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%.     

Two-qubit entangled state teleportation via optimal POVM and partially entangled GHZ state

Quantum teleportation is of significant meaning in quantum information. In this paper, we study the probabilistic teleportation of a two-qubit entangled state via a partially entangled Greenberger- Horne-Zeilinger (GHZ) state when the quantum channel information is only available to the sender. We formulate it as an unambiguous state discrimination problem and derive exact optimal positive-operator valued measure (POVM) operators for maximizing the probability of unambiguous discrimination. Only one three-qubit POVM for the sender, one two-qubit unitary operation for the receiver, and two cbits for outcome notification are required in this scheme. The unitary operation is given in the form of a concise formula, and the fidelity is calculated. The scheme is further extended to more general case for transmitting a two-qubit entangled state prepared in arbitrary form. We show this scheme is flexible and applicable in the hop-by-hop teleportation situation.     

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.     

Probabilistic Teleportation of Three-Qubit Entangled State via Five-qubit Cluster State

A scheme for probabilistic teleportation of an unknown three-qubit entangled state via a five-qubit non-maximally entangled cluster state as quantum channel is proposed. In this scheme, the sender performs two Bell state and a single-qubit measurements on the qubits, the receiver can reconstruct the original state with a certain probability by making appropriate unitary transformations and controlled-not (C-not) operations. 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.     

Probabilistic resumable quantum teleportation in high dimensions

Teleportation is a quantum information process without classical counterparts, in which the sender can disembodiedly transfer unknown quantum states to the receiver. In probabilistic teleportation through a partial entangled quantum channel, the transmission is exact (with fidelity 1), but may fail in a probability and the initial state is destroyed simultaneously. We propose a scheme for nondestructive probabilistic teleportation of high-dimensional quantum states. With the aid of an ancilla in the hands of the sender, the initial quantum information can be recovered when teleportation fails. The ancilla acts as a quantum apparatus to measure the sender's subsystem. Erasing the information recorded in it can resume the initial state.     

Controlled Teleportation Using Four-Particle Cluster State

A controlled teleportation scheme is presented. In this scheme, quantum information of a single-qubit state or an entangled two-qubits state is transmitted from a sender (Alice) to a receiver (Charlie) via a four-particle cluster state under the control of the supervisor (Bob). The feature of this scheme is that the teleportation between the sender and the receiver depends on the control of the supervisor.     

Faithful teleportation of multi-particle states involving multi spatially remote agents via probabilistic channels

We present an approach to faithfully teleport an unknown quantum state of entangled particles in a multi-particle system involving multi spatially remote agents via probabilistic channels. In our scheme, the integrity of an entangled multi-particle state can be maintained even when the construction of a faithful channel fails. Furthermore, in a quantum teleportation network, there are generally multi spatially remote agents which play the role of relay nodes between a sender and a distant receiver. Hence, we propose two schemes for directly and indirectly constructing a faithful channel between the sender and the distant receiver with the assistance of relay agents, respectively. Our results show that the required auxiliary particle resources, local operations and classical communications are considerably reduced for the present purpose.     

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.     

Controlled Teleportation of an ECS by Using a Four-Mode CTECS

A new scheme for controlled teleportation of an entangled coherent state (ECS) with the help of a four-mode cluster-type entangled coherent state (CTECS) is proposed in detail. In this scheme, a four-mode CTECS is shared by a sender, a controller and a receiver. At first, the sender performs photon number measurement on the modes at hand, and the controller also performs photon number measurement on his modes. Then the receiver can reconstruct the ECS by performing an appropriate unitary transformation on his mode after he knows the measured results of the sender and the controller. And the probability of successful controlled teleportation is approaching 1/2.     

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.     

量子隐形传态的类簇态信道方案(英文)

提出了利用一个四粒子类簇态来实现一个任意两粒子态的隐形传送方案.如果接受者能根据发送者提供的测量信息对量子态实施一个合适的幺正变换,那么隐形传送就能以一定的概率实现.由于该方案中充当量子信道的是部分纠缠态,因此该方案比以前基于最大纠缠态的方案更具有现实意义.同时研究导出一个重要的结论:可以从一个四粒子类簇态(部分纠缠态)中以一定的概率提取出一个四粒子簇态(最大纠缠态),这个概率等于成功隐形传态的概率.     

Controlled Teleportation of an Arbitrary Three-Qubit State by Using a Genuinely Entangled Six-Qubit State and a Bell-State

A new application of the genuinely entangled six-qubit state introduced recently by Borras et al. [J. Phys. A 40:13407, 2007] is investigated for the controlled teleportation of an arbitrary three-qubit state. In our scheme, a genuinely entangled six-qubit state and a Bell-state are shared by a sender (Alice), a controller (Charlie) and a receiver (Bob). Both the sender and the controller only need to perform Bell-state measurements (BSMs), the receiver can reconstruct the arbitrary three-qubit state by performing some appropriate unitary transformations on his qubits after he knows the measured results of both the sender and the controller. This controlled teleportation scheme is deterministic.     

Non-Maximally Entangled Controlled Teleportation Using Four Particles Cluster States

A new scheme for controlled teleportation with the help of a four-qubit cluster state is proposed. In this scheme, a four-particle cluster state is shared by a sender, a controller and a receiver. The sender first performs a Bell-basis measurement on the qubits at hand, and the controller performs measurements under a non-maximally entangled Bell-basis after he knows the sender’s measurement result. Then the receiver introduces an auxiliary qubit and performs some appropriate unitary transformations on his qubits. Quantum teleportation is realized after the receiver performs a local measurement on the auxiliary qubit and an appropriate unitary transformation on his qubit.     

Quantum Teleportation of an Unknown Two-Atom Entangled State Using Four-Atom Cluster State

A simply protocol for quantum teleportation of an unknown two-atom entangled state using four-atom cluster state is investigated in cavity quantum electrodynamics (QED). In this protocol, by using a one-dimensional maximally four-atom cluster state as quantum channel, an unknown two-atom entangled state can be transmitted from the sender (Alice) to the receiver without apparent joint Bell-state measurement. According to the results measured by the sender, the receiver can obtain the original state with unit successful probability. The important features of our scheme can also be demonstrated in ion trap system.     

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.     

任意 n 粒子纠缠态的概率传送及其量子逻辑线路

采用n对两粒子非最大纠缠态作为量子通道,使用纠缠交换的方法实现了n粒子任意纠缠态的概率隐形传送。在传输过程中,发送者Alice对自己所拥有的粒子进行贝尔基测量,并将测量结果通过经典通道通知远方的接收者Bob,Bob根据所获取的信息对他的粒子实行相应的幺正变换以恢复原始的粒子信息态,从而成功实现隐形传送。该方案将所有参与传送的粒子划分为n个单元,将对n 1个粒子在2n 1维基下的复杂联合幺正操作分解为n次类似的重复操作,每次重复都是对两个粒子在四维基下的简单操作,大大降低了实验实现的难度。设计了n粒子量子态概率传送的量子逻辑线路,并对每组重复操作的单元线路做了提取。传送成功的总概率为2n∏ni=1ci2。     

An Economical Scheme for Cloning an Unknown M-Qudit Equatorial-Like State with Assistance

We propose a scheme to realize quantum cloning of an unknown M-qudit equatorial-like entangled state. The first stage of the protocol requires teleportation. After the teleportation is accomplished, the receiver can reestablish the original state. In the second stage of the protocol, with the assistance （through a single-particle projective measurement） of the preparer, the perfect copy of an original state can be produced at the site of the sender. Our scheme requires a single maximally entangled qudit pair as the quantum channel and three dits classical communication. The scheme is feasible at the expense of consuming local resources which include M - 1 ancillary qudits introduced by the receiver and additional bi-qudit operations. Moreover, we construct a sort of unitary transformations which ensure ancillary qudits are not necessarily introduced by the sender. Comparing to the previous protocols, the proposed protocol is economical due to that the cost of both quantum nonlocal resources and classical communication is lowest.     

Teleportation of an Arbitrary Multipartite GHZ-Class State by One EPR Pair

We present a scheme for perfectly teleporting an arbitrary and unknown N-particle GHZ-class state from a sender to a receiver. We just need one quantum channel composed of two or three particles in the maximally entangled state. The sender performs one Bell-state measurement on two of her particles and N - 1 Hadamard operations and N - 1 yon Neumann measurements on the rest N - 1 particles. The receiver adopts one corresponding unitary transformation on his particles shared with the sender. After that, the receiver can obtain the original N-particle GHZ-class state by introducing N - 1 ancillary particles and carrying out N - 1 controlled-NOT operations. We also generalize the scheme to the case of controlled teleportation.     

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.