Assisted Quantum Computation Based On The Circuit Model

Quantum computation is based on the principles of quantum mechanics to implement computation.With the progress of quantum computation and quantum information,the research and development of quantum computer are also improving.When a scalable quantum computer is invented,it will be implemented in a “cloud” computation pattern because of its high price.In the field of quantum computation,there is a standard calculation model—quantum circuit model.Under the “cloud” computation pattern,the remote quantum server can assist the client to perform universal quantum computation by quantum circuit model.Furthermore,the client can realize quantum teleportation by the quantum circuit model.In this paper,we devise two protocols of universal assisted quantum computation based on the circuit model.One is based on the ?/8 gate,the other is based on the Toffoli gate.We also analyze the universality,half-blindness and correctness of the protocols,which can ensure that Alice will get the correct result.The innovation of the protocols is that Bob assists Alice to perform ?/8 gate in three rounds and it's the first time to put forward to performing Toffoli gate.The client(Alice)only needs the ability to receive and send qubits and perform Pauli gates.Meanwhile,the server(Bob)cannot obtain the real input and the final result.We also present two different quantum teleportation schemes,one is perfect teleportation and the other is probabilistic quantum teleportation.The innovation of the schemes is that we realize quantum teleportation of an arbitrary single-particle by a new four-particle entangled state.In the first scheme,a four-particle maximally entangled state is used as the quantum channel and the success probability is 1.In the latter scheme,the quantum channel is a four-particle non-maximally entangled state,which is a more general state and the success probability is 2(?l?~2+?m?~2)(l and m are the amplitude of the four-particle non-maximally entangled state).