Research On Quantum Dense Coding Based On Tripartite Entangled Channels

Quantum informatics,a combination of quantum mechanics and information science,is an emerging and advancing front science in information processing.The reason why quantum information processing is superior to classical information processing lies largely in the existence of quantum entanglement,which transcends classical correlation between quantum systems.Quantum dense coding based on quantum entanglement is capable of transmitting more information than classical dense coding and has taken the spotlight in terms of the realm of quantum information.Based on the basic principles of quantum mechanics,with an emphasis on controlled dense coding and simultaneous dense coding,this paper investigates problems involved with quantum dense coding.The main results are as follows:1.The specific research schemes of quantum dense coding are reviewed,these schemes consist of Bennett dense coding,controlled dense coding and simultaneous dense coding.Among them,controlled dense coding and simultaneous dense coding schemes are the extension of the former,and the amount of information transmission of three schemes is better than that of classical communication.2.Utilizing W state with strong entanglement properties as quantum channel,two equivalent probabilistic controlled dense coding schemes are designed.One,controlled dense coding is realized by introducing auxiliary particles and implementing unitary transformation under the control of the third party.Second,controlled dense coding is achieved by performing projection measurement and POVM.The result embodies that controller can control quantum channel and information transmission between sender and receiver by adjusting measurement angle ,besides the receiver gains the same amount of information in two schemes.3.Exploiting the nonlocal correlation property of -type entangled state,introducing a new locking operator double controlled-NOT(DCNOT)to lock the entangled channel,we propose a simultaneous dense coding protocol.On the one hand,the protocol ensures that two receivers can simultaneously get their respective classical information sent by a sender;on the other hand,the protocol can guarantee security against the intercept-resend attack in the communication phase by introducing additional detect quantum states.