In this paper, we present a deterministic four-party quantum cyclic controlled teleportation (QCYCT) scheme, by using a multi-qubit partially entangled state as the quantum channel. In this scheme, Alice can teleport an arbitrary [Formula: see text]-qubit state to Bob, Bob can teleport an arbitrary [Formula: see text]-qubit state to Charlie and Charlie can teleport an arbitrary [Formula: see text]-qubit state to Alice under the control of the supervisor David. We utilize rotation gate, Hadamard gates and controlled-NOT (CNOT) gates to construct the multi-qubit partially entangled channel. Only Bell-state measurements, single-qubit von-Neumann measurement and proper unitary operations are required in this scheme, which can be realized in practice easily based on the present quantum experiment technologies. The direction of cyclic controlled teleportation of arbitrary multi-qubit states can also be changed by altering the quantum channel. Analysis demonstrates that the success probability of the proposed scheme can still reach 100% although the quantum channel is non-maximally entangled. Furthermore, the proposed four-party scheme can be generalized into the case involving [Formula: see text] correspondents, which is more suitable for quantum communication networks. We also calculate the intrinsic efficiency and discuss the security of the proposed scheme. Compared with the existing QCYCT schemes which realized cyclic controlled teleportation of arbitrary single-qubit states, specific two-qubit and three-qubit states, the proposed scheme is of general significance.
In this paper, we present a deterministic four-party quantum cyclic controlled teleportation (QCYCT) scheme, by using a multi-qubit partially entangled state as the quantum channel. In this scheme, Alice can teleport an arbitrary [Formula: see text]-qubit state to Bob, Bob can teleport an arbitrary [Formula: see text]-qubit state to Charlie and Charlie can teleport an arbitrary [Formula: see text]-qubit state to Alice under the control of the supervisor David. We utilize rotation gate, Hadamard gates and controlled-NOT (CNOT) gates to construct the multi-qubit partially entangled channel. Only Bell-state measurements, single-qubit von-Neumann measurement and proper unitary operations are required in this scheme, which can be realized in practice easily based on the present quantum experiment technologies. The direction of cyclic controlled teleportation of arbitrary multi-qubit states can also be changed by altering the quantum channel. Analysis demonstrates that the success probability of the proposed scheme can still reach 100% although the quantum channel is non-maximally entangled. Furthermore, the proposed four-party scheme can be generalized into the case involving [Formula: see text] correspondents, which is more suitable for quantum communication networks. We also calculate the intrinsic efficiency and discuss the security of the proposed scheme. Compared with the existing QCYCT schemes which realized cyclic controlled teleportation of arbitrary single-qubit states, specific two-qubit and three-qubit states, the proposed scheme is of general significance.
In order to explore multi-directional quantum communication in a three-dimensional (3D) system, five-, seven- and [Formula: see text]-qutrit entangled states are constructed by 3D-Hadamard gates and 3D-controlled-NOT gates in this paper. Then a new scheme of controlled bidirectional quantum teleportation (QT) via five-qutrit entangled channel is proposed, where two observers can exchange their unknown single-qutrit states at the same time under the control of the supervisor. Along this mental, we propose a novel theoretical scheme to fulfil four-party controlled cyclic QT by using a seven-qutrit entangled state as the quantum channel, in which Alice can teleport an arbitrary unknown single-qutrit state to Bob, Bob can transmit an arbitrary single-qutrit state to Charlie, at the same time, Charlie can also teleport an arbitrary unknown single-qutrit state to Alice with the permission of the supervisor. In these schemes, only specific two-qutrit 3D-Bell state measurements, single-qutrit 3D-Z-basis measurements and suitable 3D-Weyl operators are needed, which can be implemented in physics easily. Moreover, the proposed four-party controlled cyclic scheme can be generalized into the case containing [Formula: see text] ([Formula: see text]) observers by using a [Formula: see text]-qutrit entangled channel. Analysis shows that the success probability of our schemes can reach 1. Through detailed discussion, we find that the security of our schemes and the control power of the supervisors can be guaranteed, and the intrinsic efficiency of the proposed schemes is relatively high.
To explore the multi-directional quantum communication in a three-dimensional (3D) system, 13- and [Formula: see text]-qutrit entangled states are constructed by 3D Hadamard gates and 3D controlled NOT gates in this paper. Then we propose a novel theoretical scheme to fulfill four-party double-direction cyclic controlled quantum teleportation (QT) by using a 13-qutrit entangled state as the quantum channel. In this scheme, each observer can teleport two different arbitrary unknown single-qutrit states to the other two observers under the control of the supervisor, respectively and synchronously, which realizes cyclic controlled QT in both clockwise and counterclockwise directions simultaneously. Each observer performs two 3D Bell basis measurements and the supervisor carries out a single-qutrit measurement in the 3D [Formula: see text]-basis. After hearing the measurement results from the other two observers and the supervisor, each observer can restore the target states by utilizing suitable 3D Weyl operators. Based on the [Formula: see text]-qutrit entangled channel that we construct, we exhibit in detail how to extend the presented four-party double-direction cyclic controlled QT scheme to the situation with [Formula: see text] ([Formula: see text]) observers. Analysis shows that the success probability of both the proposed four-party and [Formula: see text]-party schemes can reach 1, and these two schemes are expected to be realized experimentally in the near future. Through detailed discussion, we find that the security of our schemes and the control power of the supervisor can be guaranteed, and the intrinsic efficiency of the proposed schemes is relatively high.
In the existing research on cyclic teleportation protocols, it is generally discussed that the teleportation of single particle, two particle unknown quantum states with symmetrical structure or asymmetric special unknown quantum states (such as GHZ state) with three or four participants. In contrast, the scheme proposed in this paper has universality and stronger practicability. In this paper, we propose a novel scheme of asymmetric cyclic controlled teleportation. In our scheme, Alice can teleport an arbitrary single-qubit entangled state to Charlie, Charlie can teleport an arbitrary three-qubit entangled state to Bob and at the same time Bob can teleport an arbitrary two-qubit entangled state to Alice under the control of a controller David. It only needs Bell measurement and local unitary operation, and can realize three-party cyclic transmission with probability 1 by using a quantum channel composed of any six of the 16 G states.
In this paper, two three-party cyclic teleportation schemes for real arbitrary quantum states of a single particle and two particles are proposed for the first time. In the first ([Formula: see text]) scheme, Alice sends any single particle state to Bob, Bob sends any two-particle states to Charlie, and meanwhile Charlie sends any single particle state to Alice. In the second ([Formula: see text]) scheme, with the help of the controller David, Alice sends any two-particle states to Bob, Bob sends any two-particle states to Charlie, and Charlie sends any single particle state to Alice simultaneously. Based on the maximum entangled quantum channel shared in advance, the communication participants carry out some Bell state measurement (BSM) measurements and carry out corresponding unitary transformation according to the results published by each other. After that, the cyclic teleportation of predetermined quantum information can be successfully realized. The success probability of teleportation of both schemes can reach 100%. Finally, this paper briefly analyzes the security of the two schemes and compares them with some previously published schemes from the perspective of inherent efficiency. The results show that the two schemes proposed in this paper are safe and have high inherent efficiency. Different from the previous symmetric cyclic quantum teleportation methods, the asymmetric cyclic quantum teleportation schemes proposed in this paper are more universal.
A novel scheme is proposed in this paper, which realizes the cyclic and bidirectional teleportation via pseudo multi-qubit entangled states. To realize the teleportation completely, it utilizes controlled-NOT operation to obtain a quantum channel whose number of qubits reaches twelve. In this scheme, Alice can teleport her qubits to Bob and Charlie, Bob can teleport his qubits to Alice and Charlie while Charlie teleports his qubits to Alice and Bob, respectively, they reconstruct the original state and make the scheme perfectly by performing Bell-state measurement and appropriate unitary operation.
In this paper, by utilizing a nine-qubit entangled state as a quantum channel, we propose new schemes for symmetric and asymmetric cyclic controlled quantum teleportation (CYCQT). In our proposed schemes, four participants Alice, Bob, Charlie and David teleport their unknown quantum states cyclically among themselves with the help of a controller Eve. No participants can reconstruct the original states sent from the respective senders without the permission of the controller. Also, by considering same nine-qubit entangled state as a quantum channel, we propose a generalized scheme for CYCQT of multi-qubit states. In contrast to the previous CYCQT schemes involving three communicators and a controller, there are four communicators and a controller in the proposed schemes. Also, compared with previous CYCQT schemes, our proposed CYCQT schemes require less consumption of quantum resource and the intrinsic efficiency of the generalized scheme increases with the increase of number of qubits in the information states.