Design And Optimization On Quantum Information Transmission Protocols In The Quantum Network

Quantum communication is a new type of communication,which uses quantum entanglement to transmit information.As a new interdisciplinary subject involving quantum theory and classical information theory,it has developed rapidly during the past 20 years.It mainly includes: quantum teleportation,quantum state preparation and quantum dense coding,etc.In this thesis,we mainly discuss several important protocols such as quantum state remote preparation,quantum network coding and quantum dialogue.First of all,this thesis presents an optimized protocol for the quantum state preparation of W state.The GHZ state is firstly prepared as the quantum channel with the most easily prepared and the most common Bell states,and then an arbitrary four-qubit W state is prepared,and the protocol can be extended to the 2n-qubit W state.Then,we proposed a novel asymmetric quantum dialogue protocol.It achieves channel capacity and transfer information equal to up to five bits per round.Moreover,this protocol can avoid information leakage and fill in the blank of the asymmetric communication protocol.Finally,this thesis applies the quantum state remote preparation to the network coding model,and uses the classical quantum multiplexing channel to realize the efficient and secure remote quantum state preparation,and the fidelity reaches 1.