Study On Quantum Teleportation

Quantum information is a new cross-discipline that integrates quantum mechanics and information science.It can break through the physical limits of existing information technology and is a very important modern technology.In quantum communication,the entanglement properties of qubits are essentially used for information transmission.However,the entanglement properties of qubits are very difficult to maintain.In practice,qubits often interact with the surrounding environment and cause the entanglement to weaken,thereby affecting the correct transmission of quantum information.Therefore,in order to achieve the purpose of correct transmission of quantum information,it is necessary to clarify the influence of entanglement and the surrounding environment on the quantum communication process.The paper uses fidelity as an index to measure the quality of quantum communication.It studies the degree of entanglement of the EPR channel and the influence of four classical noises on fidelity.First,when simulating the communication process using EPR as a channel to solve the fidelity,in order to facilitate the study of the influence of entanglement on fidelity,the channel coefficient ratio is used as an index to measure the degree of entanglement.The particles are entangled by the channel for the EPR channel.The fidelity of the state contraction effect and the time cost of the EPR channel to transmit the particles,the paper studied the law between the fidelity and the channel coefficient amplitude ratio when using EPR channel to transmit 1,2,and 3 particles.The relationship between the fidelity and the amplitude ratio of the channel coefficient when transmitting N particles using the EPR channel.The study found that: First,with the different number of transmitted particles,the channel coefficient amplitude ratio range is different;Second,the fidelity can surpass the maximum fidelity of the classic channel under the condition of satisfying certain EPR channel coefficient amplitude ratio.Degree 0.67,which embodies the communication advantages of quantum communication;Third,when the number of transmitted particles is fixed,the smaller the difference between the amplitude ratios of the channel coefficients,the smaller the value range of the channel coefficient amplitude ratio that can be used for correct transmission of quantum information will follow.Decrease.The above conclusions can be used when designing an EPR quantum channel to balance the relationship between time cost and transmission success rate.Secondly,the paper uses the method of super-operator summation to interfere with the noise on the particles of quantum communication.Based on the study of the relationship between channel coefficient amplitude ratio and fidelity,the paper focuses on the interference of probabilistic quantum teleportation channels against the noise environment.The problem is that the effect of four classical noises on the fidelity in the EPR channel is studied.The four classic noises are: bit flip noise,phase flip noise,depolarization noise,and amplitude damping noise.When using the EPR channel to transmit quantum information,the noise is interfered with input particle I,channel particle A,and channel particle B,and then there are four kinds of measurement results that may be measured by Bell,corresponding to a total of 48 fidelity channel model changes.The study found that: First,the 48 fidelity channel models all have the value range of the noise interference probability and channel coefficient amplitude ratio that can enable the correct transmission of quantum information;Second,there are 6 kinds of bit flip noise interference EPR fidelity The channel model can make the fidelity meet the transmission requirements regardless of the noise superposition probability and the channel coefficient amplitude ratio;in the EPR fidelity channel model of bit flip noise,depolarization noise,and amplitude-damped noise interference There are 20 fidelity channel models demonstrating that the presence of noise can increase the fidelity value;there are 11 fidelity in the EPR fidelity channel model for bit flip,depolarization,and amplitude-damped noise interference.In the channel model,the channel coefficient amplitude ratio needs to be increased,that is,the channel entanglement is reduced to adapt to the noise to improve the fidelity of the quantum communication.That is to say,the degree of entanglement can be sacrificed to adapt to the interference of noise on the communication process so as to achieve the purpose of correct transmission of quantum information.