Experimental realization of quantum controlled teleportation of arbitrary two-qubit state via a five-qubit entangled state

Quantum controlled teleportation is the transmission of the quantum state under the supervision of a third party.This paper presents the theoretical and experimental results of an arbitrary two-qubit quantum controlled teleportation scheme,in which the sender Alice only needs to perform two Bell state measurements and the receiver Bob can perform an appropriate unitary operation to reconstruct the arbitrary two-qubit states under the control of the supervisor Charlie.The operation process of the scheme is verified on the IBM quantum experience platform,and the accuracy of the transmitted quantum state is further checked by performing quantum state tomography.Meanwhile,a good fidelity is obtained by using the theoretical density matrix and the experimental density matrix.A sequence of photonic states is introduced to analyze the possible intercept-replace-resend,intercept-measure-resend,and entanglement-measure-resend attacks on this scheme.The results proved that our scheme is highly secure.

Perfect quantum controlled teleportation via a novel threeparticle partially entangled channel

Recently Li et al. proposed special partially entangled states serving as quantum channel in quantum controlled teleportation, while there are some limitations in their scheme. Based on that, we present a possible improvement in this paper. We construct a novel three-particle partially entangled state which is suitable for perfect controlled teleportation. A simple quantum circuit is designed to obtain this state. We evaluate quantum controlled teleportation from three points of view： teleportation fidelity, success probability and the controller＇s power. Detailed calculations and simulation analyses show that the constructed state is a suitable channel for controlled teleportation of arbitrary qubits, unit teleportation fidelity and 100% success probability can be achieved. Meanwhile, as long as channel＇s entanglement degree equals to or greater than 3/4, the controller＇s power can be guaranteed.

Controlled Teleportation of Multi-qudit Quantum Information by Entanglement Swapping

In this paper, we present a scheme for teleporting multi-qudit quantum state, from the sender Alice to the receiver Charlie via many controllers Bobs, whose control parameters are obtained using entanglement swapping of maximally d-dimensional EPR pair. In our scheme, Yang＇s qutrit controlled teleportation protocol [Commun. Theor. Phys. 49 （2008） 338] based on Bell-state entanglement swapping is generalized to the qudit case. The scheme of multi-qudit owns the advantage of having higher code capacity and better security than that of multi-qutrit.

Controlled Quantum Teleportation of a One-Particle Unknown State via a Three-Particle Entangled State

A kind of three-particle entangled state is applied as quantum channel of the controlled quantum teleporration of a one-particle unknown state. The one-particle unknown state is transmitted from the sender to the recipient under the control of the supervisor. After the sender makes Bell-state measurement and the supervisor performs von Neumann measurement, the recipient carries out unitary transformation on his own particle depending on classical information from the sender and the supervisor. The teleportation cannot be completed successfully by the recipient if the supervisor does not agree to cooperate. The roles of the recipient and the supervisor may be exchanged in this scheme. The scheme is flexible and feasible because the sequence of manipulation of the sender and the supervisor may be exchanged and only simple unitary transformation is included.

A controlled quantum teleportation scheme of an N-particle unknown state via three-particle W1 states

In this paper a controlled quantum teleportation scheme of an N-particle unknown state is proposed when N groups of three-particle W1 states are utilized as quantum channels. The quantum information of N-particle unknown state is transmitted from the sender to the recipient under the control of all supervisors. It can be realized with a certain probability. After the sender makes Bell-state measurements and the supervisors perform the computational basis measurements, the recipient will introduce auxiliary particles and carry out unitary transformations depending on classical information from the sender and the supervisors. Finally, the computational basis measurement will be performed by the recipient to confirm whether the teleportation succeeds or not. The successful completion of the scheme relies on all supervisors＇ cooperation. In addition, the fidelity and security of the scheme are discussed.

Controlled quantum perfect teleportation of multiple arbitrary multi-qubit states

We present an efficient controlled quantum perfect teleportation scheme. In our scheme, multiple senders can teleport multiple arbitrary unknown multi-qubit states to a single receiver via a previously shared entanglement state with the help of one or more controllers. Furthermore, our scheme has a very good performance in the measurement and operation complexity, since it only needs to perform Bell state and single-particle measurements and to apply Controlled-Not gate and other single-particle unitary operations. In addition, compared with traditional schemes, our scheme needs less qubits as the quantum resources and exchanges less classical information, and thus obtains higher communication efficiency.

A Quantum Multi-Proxy Blind Signature Scheme Based on Entangled Four-Qubit Cluster State

In this paper, a multi-proxy blind signature scheme based on controlled quantum teleportation is proposed.Entangled four-qubit Cluster state functions as quantum channel, which needs less resource to complete the quantum multi-proxy blind signature. The scheme uses the physical characteristics of quantum mechanics to guarantee its blindness, unforgeability, and undeniability. The eavesdropping check is used to ensure the security. Our scheme has a foreseeable application to the E-business, E-governments, and etc.