Bell态隐形传输中的冯·诺依曼熵研究

Study on von Neumann Entropy in Teleportation of the Bell State

首先,运用冯·诺依曼熵计算隐形传输前纠缠态的纠缠度,分析其变化与纠缠态参数的关系;其次,运用冯·诺依曼熵计算隐形传输后所获塌缩态的纠缠度,表明纠缠度与所要传输的纠缠态参数和信道参数相关;最后,讨论当纠缠态为Bell态时,纠缠度变化与信道参数的关系.利用纠缠度刻画基于团簇态实现Bell态隐形传输前后纠缠的变化程度,由纠缠度和成功概率2个指标综合分析得出信道参数合理的选择范围.

In this paper,firstly,we use von Neumann entropy to calculate the entanglement of entangled states before teleportation,and analyze the relationship between their changes and entangled state parameters.Secondly,the entanglement degree of the collapsed state obtained by the teleportation is calculated by using von Neumann entropy.It indicates that the entanglement degree is related to the entangled state parameters and channel parameters to be transmitted.Then we discuss the relationship between entanglement change and channel parameters when the entangled state is in the Bell state.The entanglement degree is used to describe the degree of entanglement before and after the stealth transmission of the Bell state based on the cluster state.Based on the comprehensive analysis of two indexes,the entanglement degree and the success probability,the reasonable selection range of channel parameters is obtained.