Quantum Controlled Teleportation of Bell State Using Seven-Qubit Entangled State

We present a theoretical scheme for quantum controlled teleportation, which transmits a Bell state from sender Alice to remote receiver Bob via a seven-qubit entangled state under the control of supervisor Charlie. The Bell state can be transmitted if Alice performs two GHZ-state measurements on her qubits and Charlie carries out a projection measurement on her qubit, respectively. Based on the measurement results of Alice and Charlie, the original quantum state can be reconstructed on Bob's qubits via performing appropriate unitary operations. Moreover, we take comparisons with the previous schemes in five aspects of transmission qubits number, consumption of quantum resource, consumption of classical resources, success probability and intrinsic efficiency. And we also utilize decoy photons technology to ensure the security of the scheme under three kinds of attacks. We evaluated the scheme, and the results have proven that our proposed scheme has higher success probability, intrinsic efficiency and higher security.