局域测量对多粒子纠缠态纠缠度的影响

The Effect of the Local Quantum Measurements on the Entanglment Degree of Multi Particle Entangled State

本文研究了采用密度算符之间距离的概念来定义纯态纠缠态的纠缠度，并研究Ｎ个粒子纠缠态的纠缠度如何随对部分粒子进行量子测量而改变。

Using the concept of th distance between density operators, we define an entanglment degree of a pure entangled state and study how the entanglment degree changes with the local quantum measurements of the entangled state of N particles.