A Scheme of Controlled Quantum State Swapping

A scheme for controlled quantum state swapping is presented using maximally entangled five-qubit state,i.e.,Alice wants to transmit an entangled state of particle a to Bob and at the same time Bob wants to transmit an entangled state of particle b to Alice via the control of the supervisor Charlie.The operations used in this swapping process including C-not operation and a series of single-qubit measurements performed by Alice,Bob,and Charlie.     

Bidirectional Quantum Controlled Teleportation via Five-Qubit Cluster State

A theoretical scheme for bidirectional quantum controlled teleportation is presented using the entanglement property of five-qubit cluster state. This means that Alice wants to transmit a entangled state of particle a to Bob and Bob wants to transmit a entangled state of particle b to Alice via the control of the supervisor Charlie.     

Bidirectional Controlled Quantum Teleportation of Three-Qubit State by a New Entangled Eleven-Qubit State

In this paper, an improved controlled bidirectional quantum teleportation protocol of the special three-qubit state is proposed. In a little bit more detail, under the control of the third supervisor Charlie, Alice wants to send one special three-qubit entangled state to Bob, and at the meantime, Bob also wants to transmit another special three-qubit entangled state to Alice. In other words, both Alice and Bob can be the sender and receiver simultaneously. To achieve this aim, a specific eleven-qubit entangled state is shared among Alice, Bob and Charlie in advance acting as the quantum channel. Then, Alice and Bob first implement the GHZ-state measurement and Bell-state measurement respectively, and following Charlie’s single-qubit measurement. Finally, upon the foregoing measurement results, Alice and Bob can respectively implement the specific unitary operators on their local particles to recover the initial state transmitted by the other.

     

Tripartite Quantum Controlled Teleportation via Seven-Qubit Cluster State

In this paper, a theoretical scheme for tripartite quantum controlled teleportation is presented using the entanglement property of seven-qubit cluster state. This means that Alice wants to transmit a entangled state of particle a to Bob, Charlie wants to transmit a entangled state of particle b to David and Edison wants to transmit a entangled state of particle c to Ford via the control of the supervisor. In the end, we compared the aspects of quantum resource consumption, operation complexity, classical resource consumption, quantum information bits transmitted, success probability and efficiency with other schemes.     

Asymmetric Bidirectional Controlled Teleportation via Seven-qubit Cluster State

We propose a new protocol of asymmetric bidirectional controlled teleportation by using a seven-qubit cluster state as the quantum channel. That is to say Alice wants to transmit an arbitrary single-qubit state to Bob and Bob wants to transmit an arbitrary two qubit state to Alice via the control of the supervisor Charlie. One only need perform the Bell-state measurements and single-qubit measurement.     

Bidirectional Quantum Controlled Teleportation via a Maximally Seven-qubit Entangled State

A bidirectional quantum controlled teleportation scheme using a seven-qubit maximally entangled state as quantum channel is proposed. This means that Alice can transmit an arbitrary single qubit state of qubit a to Bob and Bob can transmit an arbitrary single qubit state of qubit b to Alice via the control of the supervisor Charlie.     

Bidirectional Controlled Quantum Teleportation by Using Five-Qubit Entangled State

We propose a scheme for bidirectional controlled quantum teleportation by using a genuine five-qubit entangled state. In our scheme, Alice may transmit an arbitrary single qubit state of qubit A to Bob and at the same time, Bob may transmit an arbitrary single qubit state of qubit B to Alice via the control of the supervisor Charlie.     

Asymmetric Bidirectional Controlled Teleportation by Using Six-qubit Cluster State

We propose a scheme for asymmetric bidirectional controlled teleportation by using a six-qubit cluster state as quantum channel. 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 under the control of the supervisor Charlie.     

Bidirectional Quantum Controlled Teleportation via a Six-Qubit Entangled State

A new application of six-qubit entangled state introduced by Chen et al. (Phys. Rev. A 74, 032324, 2006) is studied for the bidirectional quantum controlled teleportation. In our scheme, a six-qubit entangled state is shared by Alice, Bob and Charlie, Alice and Bob can transmit simultaneously an arbitrary single-qubit state to each other under the control of the supervisor Charlie.     

Scheme for Asymmetric and Deterministic Controlled Bidirectional Joint Remote State Preparation

The scheme for asymmetric and deterministic controlled bidirectional joint remote state preparation by using one ten-qubit entangled state as the quantum channel is proposed. In this scheme, Alice and David want to remotely prepare an arbitrary single-qubit state at Bob's site, at the same time, Bob and Eve wish to help Alice remotely prepare an arbitrary two-qubit entangled state. Alice and Bob can simultaneously prepare the desired states with the cooperation of David and Eve under the control of Charlie.     

Bidirectional Quantum Controlled Teleportation of Three-Qubit State by Using GHZ States

In this paper, we present a scheme of bidirectional quantum controlled teleportation of three-qubit state by using GHZ states. Alice transmits an unknown three-qubit entangled state to Bob, and Bob transmit an unknown three-qubit entangled state to Alice via the control of the supervisor Charlie. In order to facilitate the implementation in the experimental environment, the preparation method of quantum channel is given. This scheme is based on that three-qubit entangled state are transformed into two-qubit entangled state and single qubit superposition state by using Toffoli Gate and Controlled-NOT operation, receivers can by introducing the appropriate unitary transformation and auxiliary particles to reconstruct the initial state. Finally, this paper is implemented a scheme of bidirectional quantum controlled teleportation of more than two qubits via the control of the supervisor Charlie.

     

N粒子W纠缠态的隐形传输

提出使用纠缠交换的方法,采用N对二粒子非最大纠缠态作为量子通道来传输N粒子W纠缠态的方案。传输过程中,发送者对自己所拥有的粒子进行Bell基测量,并将测量结果通过经典通道通知接收者,接收者根据所获取的信息对她的粒子实行相应的幺正变换以恢复最初待传输的粒子态,从而,成功实现该隐形传输。文章还以三粒子的传输为例作了详细介绍。     

控制的量子隐形传态和控制的量子安全直接通信

我们提出了一个控制的量子隐形传态方案。在这方案中，发送方Alice 在监督者Charlie的控制下以他们分享的三粒子纠缠态作为量子通道将二能级粒子未知态的量子信息忠实的传给了遥远的接受方Bob。我们还提出了借助此传态的控制的量子安全直接通信方案。在保证量子通道安全的情况下， Alice直接将秘密信息编码在粒子态序列上，并在Charlie控制下用此传态方法传给Bob。Bob可通过测量他的量子位读出编码信息。由于没有带秘密信息的量子位在Alice 和Bob之间传送，只要量子通道安全， 这种通信不会泄露给窃听者任何信息， 是绝对安全的。这个方案的的特征是双方通信需得到第三方的许可。     

Controlled Entanglement Swapping for Continuous Variables

We propose a scheme for controlled entanglement swapping of continuous variable, where an EPR pair shared by two parties （Alice and Debbie） and a GHZ entangled state shared by three parties （Alice, Bob and Claire） are required. One optical beams of the EPR state will be entangled with the output mode displaced by Bob with the help of Claire. It is shown that the entanglement swapping can occur controlled by the third party （Claire）     

Quantum Information Splitting of Arbitrary Three-qubit State by Using Five-qubit Cluster state and GHZ-state

In this paper, a new scheme of quantum information splitting (8QIS) by using five-qubit state and GHZ-state as quantum channel is proposed. The sender Alice performs Bell-state measurements (BSMs) on her qubit-pairs respectively,then tells her measurement result to the receivers Bob. If Bob wants to reconstruct the original states, he must cooperates with the controller Charlie, that Charlie performs two single particle measurement on his qubits and tells Bob the results. According to Alice’s and Bob’s results, Bob can reconstruct the initial state by applying appropriate unitary operation.     

Controlled Cyclic Remote Preparation of an Arbitrary Single-Qudit State by Using a Seven-Qudit Cluster State as the Quantum Channel

We present a protocol for controlled cyclic remote preparation of an arbitrary single-qudit state via a seven-qudit cluster state. In the protocol, Alice can help the remote agent Bob prepare an arbitrary single-qudit state, Bob can help the agent Charlie prepare an arbitrary single-qudit state and at the same time Charlie can help Alice prepare an arbitrary single-qudit state under the controller David’s control. Alice, Bob and Charlie first perform positive operator-valued measurement (POVM) on their entangled particles according to the information of the prepared state, then perform generalized X-basis measurement. The controller performs generalized X-basis measurement on his entangled particle. The arbitrary single-qudit states can be cyclic remote prepared under the controller’s control. The protocol is more convenient in application since it only requires single-particle measurement and single-particle unitary operations for controlled cyclic remote preparation of the single-qudit states.

     

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.     

Teleportation of N-Particle Entangled GHZ State via Entanglement Swapping

In this scheme, N non-maximally entangled particle pairs are used as quantum channel to teleport an unknown N-particle entangled GHZ state via entanglement swapping. In order to realize this teleportation, the sender Alice operates Bell-state measurement on particles belonging to herself. Then she informs the results to the receiver Bob through classical communication. According to the results, Bob operates corresponding transformation to reconstruct the initial state. The advantage of this scheme is that it needs only one common unitary matrix for Alice＇s different results, which has a more general meaning. As a special case, teleporting an unknown three-particle entangled GHZ state is proposed.     

A Bidirectional Teleportation Protocol for Arbitrary Two-qubit State Under the Supervision of a Third Party

In this paper we introduce a controlled teleportation protocol for transferring arbitrary two-qubit states bilaterally between Alice and Bob. The bidirectional teleportation protocol is supervised by a controller Charlie. A ten-qubit entangled quantum channel shared between Alice, Bob and Charlie is utilized. The protocol depends on Bell state measurements by Alice and Bob and single-qubit measurements by Charlie.     

Quantum Splitting a Two-qubit State with a Genuinely Entangled Five-qubit State

A new application of the genuinely entangled five-qubit state is investigated for quantum information splitting of a particular type of two-qubit state. In this scheme, a genuinely entangled five-qubit state is shared by Alice (a sender), Charlie (a controller) and Bob (a receiver), and Alice only needs to perform two Bell-state measurements and Charlie performs a single-qubit measurement, Bob can reconstruct the two-qubit state by performing some appropriately unitary transformations on his qubits after he knows the measured results of both Alice and Charlie. This quantum information splitting scheme is deterministic, i.e. the probability of success is 100 %. The presented protocol is showed to be secure against certain eavesdropping attacks.