A scheme of two-way teleportation was proposed,with GHZ quadripartite entangled state as quantum channel.Two sides of communication(Alice and Bob) shared two pairs of GHZ quadripartite entangled state in advance.After communication,Alice and Bob performed quantum projection measurement on their own qubits respectively,and announced the measured results via classical channel.Then according to the measured results presented by the other party,Alice and Bob can make appropriate unitary transformations that its own party can reconstruct the opposite quantum state information,and thus the whole two-way teleportation was realized.As long as the both sides of communication chose the suitable GHZ entangled state as quantum channel and distributed the entangled partites imparity and properly in advance,two-way teleporting including unknown general one qubit and two qubits entangled Bell state or three qubits entangled GHZ state could be realized respectively.
A scheme of two-way teleportation was proposed,with GHZ quadripartite entangled state as quantum channel.Two sides of communication(Alice and Bob) shared two pairs of GHZ quadripartite entangled state in advance.After communication,Alice and Bob performed quantum projection measurement on their own qubits respectively,and announced the measured results via classical channel.Then according to the measured results presented by the other party,Alice and Bob can make appropriate unitary transformations that its own party can reconstruct the opposite quantum state information,and thus the whole two-way teleportation was realized.As long as the both sides of communication chose the suitable GHZ entangled state as quantum channel and distributed the entangled partites imparity and properly in advance,two-way teleporting including unknown general one qubit and two qubits entangled Bell state or three qubits entangled GHZ state could be realized respectively.
A scheme for controlled two-way quantum teleportation of unknown one-qubit state via GHZ quadripartite entangled state was proposed.Two sides of communication(Alice and Bob)and the controller,secretly share two pairs of GHZ quadripartite entangled state in advance to construct quantum channel.According to the different ways of distribution along with different measuring vectors choosed to use,two-way quantum teleportation controlled by a third party and a fouth party were realized.After communication,Alice and Bob perform quantum projection measurement on parts of their qubits respectively.If the controller agrees to intercommunication,he should measure his qubits and announce the results via classical channel.Then the both sides of communication can make appropriate unitary transformations on their own certain qubit on the basis of the controller′s results,thus they are able to reconstruct each other′s unknown state on their own qubit.The security of the whole two-way communication is greatly impoved owing to the join of the third party Charlie and the fourth party Dennis.
A scheme of two-way teleportation is proposed,with Bell entangled state as Quantum Channel(QC).Firstly,two sides of communication(Alice and Bob),share two EPR entangled states.After communication,Alice and Bob perform Bell-state joint measurements to their own qubits respectively,and announce the measured results via Classical Channel(CC).Then according to the measured results,Alice and Bob make relevant unitary transformations,namely,its own party can reproduce the opposite quantum state information,and thus the two-way teleportation is realized.In order to enhance the security of two-way teleportation,and the analysis result indicates that the system′s security will strengthen with the increase of the control particles,but the security will not strengthen when the control particles increase to a certain number.
In this paper, a theoretical scheme for bidirectional quantum teleportation by using a four-qubit GHZ state and two Bell states as a quantum channel is proposed. In this scheme, two arbitrary single-qubit quantum states and an unknown three-qubit state can be mutually transmitted between the two communication participants Alice and Bob. The quantum state information can be transmitted if Alice performs four single-qubit measurement operations on her qubits and Bob carries out a four-qubit joint measurement on his qubits, respectively. Then both Alice and Bob can reconstruct the target quantum state by means of appropriate unitary operations. Then we take comparisons with the other bidirectional quantum teleportation protocols in five aspects of quantum information bits transmitted, necessary operations, consumption of quantum resource, consumption of classical resource and intrinsic efficiency. Furthermore, we use channel authentication method to ensure the channel security and prove that our protocol can withstand four attack scenarios. It is concluded that our scheme has significant advantages of more qubits number transmitted, higher intrinsic efficiency and high security.
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.
In the past decades, various schemes of teleportation of quantum states through different types of quantum channels (a prior shared entangled state between the sender and the receiver), e.g. EPR pairs, generalized Bell states, qubit GHZ states, standard W states and its variations, genuine multiqubit entanglement states, etc., have been developed. Recently, three-qutrit quantum states and two-qudit quantum states have also been considered as quantum channels for teleportation. In this paper, we investigate the teleportation of an unknown qudit using a d level GHZ state, i.e. a three-qudit maximally entangled state, as quantum channel. We design a general scheme of faithful teleportation of an unknown qudit using a d-level GHZ state shared between the sender and the receiver, or among the sender, the receiver and the controller; an unknown two-qudit of Schmidt form using a d level GHZ state shared between the sender and the receiver; as well as an unknown arbitrary two-qudit using two shared d level GHZ states between the sender, the receiver and the controller, or using one shared d level GHZ state and one shared generalized Bell state. We obtain the general formulas of Alice's measurement basis, Charlie's measurement basis and Bob's unitary operations to recover the input state of Alice. It is intuitionistic to generalize the protocols of teleporting an arbitrary two-qudit state to teleporting an arbitrary n-qudit state.
Quantum mechanics shows superiority than classical mechanics in many aspects and quantum entanglement plays an essential role in information processing and some computational tasks such as quantum teleportation (QT). QT was proposed to transmit the unknown states, in which EPR pairs, the entangled states, can be used as quantum channels. In this paper, we present two simple schemes for teleporting a product state of two arbitrary single-particle and an arbitrary two-particle pure entangled state respectively. Alice and Bob have shared an entangle state. Two Bell states are used as quantum channels. Then after Alice measuring her qubits and informing Bob her measurement results, Bob can perfectly reconstruct the original state by performing corresponding unitary operators on his qubits. It shown that a product state of two arbitrary single-particle and an arbitrary two-particle pure entangled state can be teleported perfectly, i.e. the success probabilities of our schemes are both 1.