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.     

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 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.     

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.     

Tripartite Controlled Teleportation via a Seven-Qubit Entangled State

We demonstrate that a seven-qubit entangled state can be used to realize the deterministic tripartite controlled teleportation by performing Bell-state measurements, where Alice wants to teleport an arbitrary single-qubit state of qubit a to Bob, Charlie wants to teleport an arbitrary single-qubit state of qubit b to David and at the same time Edison wants to teleport an arbitrary single-qubit state of qubit c to Ford via the control of the supervisor Tom.     

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.

     

Controlled Bidirectional Hybrid of Remote State Preparation and Quantum Teleportation via Seven-Qubit Entangled State

We propose a new protocol of implementing four-party controlled joint remote state preparation and meanwhile realizing controlled quantum teleportation via a seven-qubit entangled state. That is to say, Alice wants to teleport an arbitrary single-qubit state to Bob and Bob wants to remotely prepare a known state for Alice via the control of supervisors Fred and David. Compared with previous studies for the schemes of solely bidirectional quantum teleportation and remote state preparation, the new protocol is a kind of hybrid approach of information communication which makes the quantum channel multipurpose.     

Asymmetric Controlled Bidirectional Remote State Preparation by Using a Ten-qubit Entangled State

We present a novel scheme for asymmetric controlled bidirectional remote state preparation (ACBRSP) with complex coefficients via a ten-qubit entangled state as the quantum channel. In this scheme, two distant parties, Alice and Bob are not only senders but also receivers, and Alice wants to remotely prepare a single-qubit state at Bob’s site, at the same time, Bob wishes to help Alice remotely prepares an arbitrary two-qubit entangled state. It is shown that, only if the two senders and the controller collaborate with each other, the ACBRSP can be completed successfully. We demonstrate that the total success probability of the ACBRSP in this scheme can reach 1, that is, the scheme is deterministic.     

Schemes for Hybrid Bidirectional Controlled Quantum Communication via Multi-qubit Entangled States

We present two schemes for hybrid bidirectional controlled quantum communication (HBCQC) via six- and nine-qubit entangled states as the quantum channel, respectively. In these schemes, two distant parties, Alice and Bob are not only senders but also receivers, and Alice wants to teleport an unknown single-qubit state to Bob, at the same time, Bob wishes to help Alice remotely prepares an arbitrary single- and two- qubit state, respectively. It is shown that, only if the two senders and the controller collaborate with each other, the HBCQC can be completed successfully. We demonstrate, in our both schemes, the total success probability of the HBCQC can reach 1, that is, the schemes are deterministic.     

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.     

Bidirectional and Asymmetric Controlled Quantum Information Transmission via Five-qubit Brown State

We put forward a new protocol of deterministic controlled bidirectional quantum information transmission, using a five-qubit Brown state. That is to say Alice wants to teleport an arbitrary single-qubit state to Bob and Bob wants to remotely prepare a known state for Alice via the control of the supervisor Charlie. In terms of physical implementations, only a CNOT gate, one Bell-state measurement and one qubit measurement are used in our protocol. Compared with previous study for solely bidirectional quantum teleportation and solely bidirectional remote state preparation schemes, our protocol is a kind of hybrid approach of information communication which makes the quantum channel multipurpose, i.e., no matter whether the transmitted state is known or unknown, the state information can be transmitted with each other via a five-qubit Brown state under the control of the third party as a supervisor.     

Bidirectional Controlled Quantum Communication by Using a Seven-Qubit Entangled State

We propose a protocol for bidirectional controlled quantum communication by using a seven-qubit entangled state. In our protocol, Alice can teleport an arbitrary unknown two-qubit state to Bob, at the same time Bob can help Alice remotely prepares an arbitrary known single-qubit state. It is shown that, with the help of the controller Charlie, the total success probability of our protocol can reach 100%.     

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 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.     

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.     

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.     

Bidirectional Controlled Teleportation via Six-Qubit Cluster State

We present a scheme for bidirectional controlled teleportation by using a six-qubit cluster state as quantum channel. Based on the C-not operation and single qubit measurements, Alice may transmit an arbitrary single qubit state of qubit A to Bob and Bob may transmit an arbitrary single qubit state of qubit B to Alice via the control of the supervisor Charlie.     

Bidirectional Controlled Teleportation by Using a Five-Qubit Composite GHZ-Bell State

We present a scheme for bidirectional controlled teleportation by using a five-qubit composite GHZ-Bell state as quantum channel. Based on the C-not operation and single qubit measurements, Alice may transmit an arbitrary single qubit state of qubit A to Bob and Bob may transmit an arbitrary single qubit state of qubit B to Alice via the control of the supervisor Charlie.     

Quantum Cyclic Controlled Teleportation of Unknown States with Arbitrary Number of Qubits by Using Seven-qubit Entangled Channel

A novel theoretical scheme is proposed to implement quantum cyclic controlled teleportation (QCYCT) of three unknown states by utilizing a seven-qubit entangled state as the quantum channel, where Alice can transmit an unknown m-qubit state to Bob, Bob can transmit an unknown n-qubit state to Candy and Candy can transmit an unknown t-qubit state to Alice under the control of the supervisor David. Only controlled-not (CNOT) operations, Bell-state measurements, a single-qubit measurement and appropriate unitary operations are needed in this scheme, which can be realized in experiment easily. The desired state of each communicator can be recovered deterministically by using auxiliary particles. The direction of the cyclic controlled teleportation can also be altered throughout changing the selection of the particle pairs to be measured of each communicator. Compared with the previous QCYCT schemes, the proposed scheme possesses higher intrinsic efficiency in most cases and can transfer as many qubits as the communicators desire.