Research On Multiparty Quantum Communication Protocol Based On Cluster States

Quantum communication is a new type of communication method based on quantum entanglement.As an important quantum entanglement resource,cluster states have been widely concerned in many quantum information processing tasks,due to its maximum connectivity and reliable security.Moreover,under normal circumstances,it is impossible to maintain maximally entangled state at one's disposal due to the inevitable environmental noise,which has a non-negligible impact on the information transmission process,Taking this into consideration,we mainly study the multiparty quantum communication protocol based on cluster states,and introduce intermediate nodes to solve the problem of weak couplings between distant qubits.The main results are summarized as follows(1)The scheme for long-distance expansion of cluster state based on Bell states is proposed.In this scheme,the main unitary operations are performed by the central node,which could reduce the complexity of the implementation and make it more feasible physically.In addition,the nodes that do not directly share entanglement with each other can realize quantum communication,which improves the adaptation of the scheme(2)The scheme for multi-hop teleportation of an unknown four-qubit cluster state based on cluster states is presented.In this scheme,intermediate nodes are introduced for multi-hop teleportation between two distant nodes.In addition,we derive the unitary matrixes for establishing direct channel between two distant nodes and deduce the relationship between the coefficients of the entangled cluster states and the success probability of teleportation,which reduces the computational complexity and resource consumption significantly.(3)The scheme for remote preparation of a four-qubit cluster states based on cluster states is proposed.In this scheme,the quantum entangled channel between two distant nodes can be established through entanglement swapping.Then,the amplitude modulation,phase modulation and other operations are performed by participants to implement our protocol.Moreover,we generalize the scheme to a scenario via non-maximally entangled cluster states,which makes our scheme more flexible.