Cavity-Assisted Atomic External Momenta State Teleportation

The quantized momentum eigenstates of neutral atoms offer high resistance to decoherence and thus suggests a viable alternative for quantum informatics tasks including teleportation. In this work, a scheme is suggested to teleport an unknown superposition of two distinct external momentum states of a neutral atom onto the similar momentum states of a distant atom at the receiving end through the off-resonant atomic Bragg diffraction (ABD). In order to teleport this unknown state from the sender, that is, Alice, to the receiver, that is, Bob, a pre-existing entangled link formed through a high-Q cavity at Alice's end and momentum states of a neutral atom at the Bob's end are utilized. Further, while citing the realistic experimental parameters, it is demonstrated that the proposal can easily be implemented experimentally under the prevailing cavity-QED atom-field research scenario. The proposal is also generalized to cover the teleportation of the multipartite entangled momenta states and the case of multipartite GHZ entangled states is elucidated in details. However, the procedure is generic and can be extended to cover the teleportation schematics for any arbitrary atomic momenta states.     

Quantum Teleportation of Five-qubit State

We propose a novel quantum teleportation protocol for certain class of five-qubit state with a seven-qubit cluster state as quantum channel. In our scheme, the sender merely needs to perform a seven-qubit von-Neumann projective measurement, the original state with deterministic probability can be reconstructed by the receiver after a series corresponding unitary transformations. Compared with other schemes proposed before, our scheme has the distinct advantages of requiring fewer quantum channels, possessing higher intrinsic efficiency, and transmitting more quantum information bits.     

Standard Quantum Teleportation and Controlled Quantum Teleportation of an Arbitrary N-Qubit Information State

We explicitly present precise and simple protocols for standard quantum teleportation and controlled quantum teleportation of an arbitrary N-qubit information state and analyse the case of perfect teleportation using general quantum channels and measurement bases. We find condition on resource quantum channel and Bell states for achieving perfect quantum teleportation. We also find the unitary transformation required to be done by Bob for perfect quantum teleportation and discuss the connection with others related works. We also discuss how perfect controlled quantum teleportation demands a correct choice of the measurement basis of additional party.     

Probabilistic Teleportation of Multi-particle d-Level Quantum State

The general scheme for teleportation of a multi-particle d-level quantum state is presented when m pairs of partially entangled particles are utilized as quantum channels. The probabilistic teleportation can be achieved with a successful probability of $ \prod \limits_{N=0}^{d-1} ({C_0^N})^2/{d^M}$, which is determined by the smallest coefficients of each entangled channels.     

Quantum Teleportation of Tripartite Arbitrary State via W State

A scheme of teleportation of a tripartite state via W state is suggested. The W state serves as quantum channels. Standard Bell-state measurements and Von Neumann measurements are performed. After the sender operates the measurements and informs the receiver her results＇ he can reconstruct the original state by the corresponding unitary transformation. The probability of the successful teleportation is also obtained.     

Quantum Teleportation of Eight-Qubit State via Six-Qubit Cluster State

A novel quantum teleportation protocol for certain class of eight-qubit state is proposed. We utilize a six-qubit cluster state as quantum channel. In our scheme, the sender performs four controlled-NOT operations and a six-qubit von-Neumann projective measurement, the original state with deterministic probability can be reconstructed by the receiver. Higher efficiency can be achieved based on our results.     

Quantum Teleportation of Tripartite Arbitrary State via W State

A scheme of teleportation of a tripartite state via W state is suggested. The W state serves as quantum channels. Standard Bell-state measurements and Von Neumann measurements are performed. After the sender operates the measurements and informs the receiver her results, he can reconstruct the original state by the corresponding unitary transformation. The probability of the successful teleportation is also obtained.     

Canonical Quantum Teleportation of Two-Particle Arbitrary State

The canonical quantum teleportation of two-particle arbitrary state is realized by means of phase operator and number operator. The maximally entangled eigenstates between the difference of phase operators and the sum of number operators are considered as the quantum channels. In contrast to the standard quantum teleportation, the different unitary local operation of canonical teleportation can be simplified by a general expression.     

Canonical Quantum Teleportation of Two-Particle Arbitrary State

The canonical quantum teleportation of two-particle arbitrary state is realized by means of phase operator and number operator. The maximally entangled eigenstates between the difference of phase operators and the sum of number operators are considered as the quantum channels. In contrast to the standard quantum teleportation, the different unitary local operation of canonical teleportation can be simplified by a general expression.     

三能级单量子态控制双向量子隐形传态

采用张量表示和广义三维贝尔基测量的方法,提出了实现三能级单量子态控制双向量子隐形传态的协议.协议中,控制者Carol的量子态为任意广义三维贝尔基.选择六粒子纠缠态作为量子通道,并给出了判断任意六粒子纠缠态能否作为量子通道的必要条件.基于该条件,借助SO(3)群元素的幺正性,选择其任意两个元素作为幺正矩阵,给出了构建量子通道的一般方法.列举了两个具体构建量子通道的例子,其中Alice、Bob、Carol共同作用,进行相应的广义三维贝尔基测量和对应的幺正变换,最终实现了Alice和Bob之间量子态的交换,从而验证了所提协议的可行性.     

Quantum Teleportation via GHZ-like State

We propose an efficient teleportation scheme for an unknown state to either one of two receivers via GHZ-like states. We also discuss the fidelity of the quantum state when the control party is uncooperative.     

Multi-state Quantum Teleportation via One Entanglement State

A multi-sender-controlled quantum teleportation scheme is proposed to teleport several secret quantum states from different senders to a distance receiver based on only one Einstein-Podolsky-Rosen (EPR) pair with controlled-NOT (CNOT) gates. In the present scheme, several secret single-qubit quantum states are encoded into a multi-qubit entangled quantum state. Two communication modes, i.e., the detecting mode and the message mode, are employed so that the eavesdropping can be detected easily and the teleported message may be recovered efficiently. It has an advantage over teleporting several different quantum states for one scheme run with more efficiency than the previous quantum teleportation schemes.     

Multi-state Quantum Teleportation via One Entanglement State

A multi-sender-controlled quantum teleportation scheme is proposed to teleport several secret quantum states from different senders to a distance receiver based on only one Einstein-Podolsky-Rosen （EPR） pair with controlled-NOT （CNOT） gates. In the present scheme, several secret single-qubit quantum states are encoded into a multi-qubit entangled quantum state. Two communication modes, i.e., the detecting mode and the message mode, are employed so that the eavesdropping can be detected easily and the teleported message may be recovered efficiently. It has an advantage over teleporting several different quantum states for one scheme run with more efficiency than the previous quantum teleportation schemes.     

利用Bell态实现量子隐形传态

量子隐形传态利用了量子的纠缠特性,在物理层实现了不可破译的量子密码通信.文章从信息论的角度描述了量子纠缠态的特性,给出了实现量子纠缠态的物理门线路;利用该量子纠缠态的量子线路,分析隐形传态的通信模型,给出了利用Bell态实现隐形传态的简单结构的量子线路,证明该量子线路是可行的,为进一步研究量子密码通信提供参考.     

Optimal Schemes for Quantum Teleportation of Ten-Qubit State

A teleportation protocol for certain class of ten-qubit state by utilizing an eight-qubit entangled state as a quantum channel has been proposed. In this paper, we present an optimal scheme for the teleportation of a ten-qubit state by using a stochastic local operation and classical communication(SLOCC) equivalent to four-qubit χ state as entanglement channel. Only von Neumann type measurement, controlled-not (CNOT) operations and appropriate unitary operations are needed in this scheme. Receiver Bob can reconstruct the initial state by introducing the appropriate unitary transformation and auxiliary particles.

     

Teleportation of Two-Mode Quantum State of Continuous Variables

Using two Einstein-Podolsky-Rosen pair eigenstates $|\eta\rangle$ as quantum channels, we study the teleportation of two-mode quantum state of continuous variables.     

Quantum Teleportation of a Two Qubit State Using GHZ-Like State

Recently Yang et al. (Int. J. Theor. Phys. 48:516, 2009) had shown that using a particular type of GHZ- Like state as quantum channel, it is possible to teleport an arbitrary unknown qubit. We investigate this channel for the teleportation of a particular type of two qubit state.     

关于单模最小关联混态的量子隐性传态及其保真度的研究

基于Braunstein和Kimble方案以双模压缩真空态作为量子信道实施对单模最小关联混态量子隐性传态的可行性进行了研究.我们发现,单模最小关联混态在一定参数范围内呈现出压缩效应这种非经典性质,利用双模压缩真空态作为量子通道可以高保真的传递没有压缩效应的单模最小关联混态,但对呈现压缩效应的单模最小关联混态进行量子隐性传送时得到输出态的保真度较低.而且发现通过调节输出端位移因子的方法不能实现对单模最小关联混态保真度的优化.     

Bidirectional Quantum Teleportation by Using Five-qubit Cluster State

We propose a scheme for bidirectional quantum teleportation by using a five-qubit cluster state. In our scheme, Alice can transmit an arbitrary two-qubit entangled state to Bob and at the same time Bob can teleport an arbitrary single-qubit state to Alice.