XY模型中的量子纠缠和量子相变

Negativity as Entanglement Degree of the XY Spin Chain

为了研究自旋链模型的物理性质,采用近似计算的方法计算了XY模型中不连续子系统的Negativity,结果发现其在h=1处不连续,即发生量子相变。解决了XY模型中由于只在最近邻和次最近邻两自旋间存在纠缠造成的无法研究该模型中纠缠与距离之间的关系问题。

In order to probe into the physical property of spin chain model, we calculated the Nega- tivity of non-consecutive subsystem in XY model with approximate method. It is very interesting to find that the Negativity does not continuous at the point of h=l, in other words, quantum phase transi- tion is occurred. This paper shell light on the general relation of entangle and distance in XY model. In XY model, the entangle only between nearest neighbours next-nearest neighbors are researched.