A Novel Protocol for Bidirectional Controlled Quantum Teleportation of Two-Qubit States Via Seven-Qubit Entangled State in Noisy Environment

In this paper, a novel protocol of bidirectional controlled quantum teleportation (BCQT) via seven-qubit state is proposed. Where Alice and Bob, two legitimate users, can teleport two-qubit states to each other. In the whole process, users achieve the initial state based on preprocessing of quantum channel, Bell-state measurement (BSM), single-qubit measurement (SM), unitary operations and so on. The main superiority of the proposed protocol is more efficient compared with previous work. In addition, the proposed protocol is considered in noisy channel, it shows that the fidelities under amplitude-damping (AD) and phase-damping (PD) noise only rest with the amplitude parameter of the initial state and the decoherence noisy rate.