Quantum Teleportation Of Two-particles Entangled States And Its Application In Simultaneous Dense Coding

Quantum communication has gained favor on researchers based on its unconditional security and efficiency with the constant advance and improvement of information technology,and quantum communication was obtained rapid growth.The quantum communication has covered the main areas of quantum teleportation and quantum dense coding,quantum teleportation is types of communication of transmission of quantum state is bases on principle of nonlocality of quantum entanglement and it has the advantage of security and efficiency.The process of quantum dense coding and quantum teleportation are the inverse of each other,and quantum dense coding can obtain two classical bits of information by transmitting one qubit and increases the capacity of channel.Quantum dense coding and quantum teleportation are holding sway in quantum communication,and there are many problems remain unsettled.Several relevant works have been done on the problem of quantum teleportation protocol,quantum dense coding protocol,quantum cost and transmission of quantum state under the noise in this thesis.In order to cope with these of problem of quantum cost required for implementation in physical experiment in quantum teleportation protocol and quantum dense coding protocol,and we have proposed corresponding of quantum circuit and calculated the required of quantum cost of quantum dense coding and quantum teleportation.We also analyze the performance of quantum protocol under the noises.The main content is as follows:1.In this paper,we have designed the quantum circuit of 8 types of GHZ states,and it based on traditional of quantum teleportation protocol of three-particle entangled GHZ states as quantum channel for transmitting an arbitrary two-particle entangled states.Based on that,we have calculated quantum cost of transmit the entangled state of an arbitrary two-particle based on the different types of GHZ channels.In addition,we also find that the quantum cost required by different types of GHZ entanglement as quantum channel is different.Since the fidelity can reflect the degree of approximation of two quantum states,and we can verify the performance of quantum protocol by calculating the fidelity between the initial state and transmission state under the noises.According to theoretical research and actual situation,in presence of noise,we have also studied and calculated that the fidelity of quantum protocol and the variations of fidelity against with the noise parameter are described intuitively by graphics.The findings show that the growth of noise parameters will be reduced the fidelity of quantum states,and will be impact on performance of the communication.2.In this paper,we have proposed a novel locking operator and a simultaneous dense coding protocol for three receivers based on Bell states based on traditional of simultaneous dense coding protocol.The locking operator can lock the quantum entanglement channels and receivers cannot obtain useful information without a collaboration to perform the unlocking operation,which can guarantee the information’s security.And in the second place,we have calculated the quantum cost of this protocol based on quantum circuit.Based on that,we have also calculated the joint success probabilities of three-party receivers and respective success probability and we also find that success probability of the three-party receivers are independent of the encode message.