Controlled joint remote preparation of an arbitrary N-qubit state

In this paper, a novel scheme for controlled joint remote preparation of an arbitrary N-qubit state is proposed. In the scheme, Alice and David prepare an arbitrary N-qubit state on Bob’s side under the control of Charlie by using a 3N + 1-qubit entangled state as the quantum channel. First, the quantum channel is constructed through the Hadamard and controlled-NOT operations. Then, Alice, David, and Charlie each perform the quantum measurements on their own qubits. To ensure that the original state can be prepared determinately, two algorithms are proposed to construct the measurement bases for Alice and David. Finally, Bob reconstructs the original state with several appropriate unitary operations on his qubits according to the measurement results of Alice, David, and Charlie. To demonstrate the feasibility of the scheme, a remote preparation example of an arbitrary two-qubit state with the scheme is given. At the end of this paper, the efficiency analysis of the scheme and some conclusions is presented. In comparison with previous schemes, the scheme is superior in terms of the capability and efficiency of quantum communication.