Zeng Shi-Ping, Shi Hai-Long, Zhou Xu, Wang Xiao-Hui, Liu Si-Yuan, Hu Ming-Liang
Institute of Modern Physics, Northwest University, Xi'an, 710127, China.
School of Physics, Northwest University, Xi'an, 710127, China.
Sci Rep. 2019 Jan 31;9(1):1083. doi: 10.1038/s41598-018-37474-x.
The differences between the XXZ model with topological and periodical boundary conditions were compared by studying their entanglement, quantum discord, and critical temperature above which the entanglement vanishes. It shows that the different boundary conditions mainly affect bipartite quantum correlations of the boundary spins rather than that of other spin pairs. The topological boundary spins can protect entanglement and discord against strong magnetic fields while the periodical boundary spins can protect them against nonuniform magnetic fields. Compared with the periodical XXZ model, the critical temperature is significantly improved for the topological XXZ model. The topological XXZ model also allows us to improve significantly its critical temperature by increasing the strength of magnetic field, which is not feasible for the periodical XXZ model. It is therefore more promising for preparing entangled states at high temperature in the topological XXZ model.
通过研究具有拓扑和周期性边界条件的XXZ模型的纠缠、量子失协以及纠缠消失时的临界温度，比较了它们之间的差异。结果表明，不同的边界条件主要影响边界自旋的二分量子关联，而非其他自旋对的二分量子关联。拓扑边界自旋可以保护纠缠和失协免受强磁场影响，而周期性边界自旋可以保护它们免受非均匀磁场影响。与周期性XXZ模型相比，拓扑XXZ模型的临界温度显著提高。拓扑XXZ模型还允许我们通过增加磁场强度来显著提高其临界温度，这对周期性XXZ模型是不可行的。因此，在拓扑XXZ模型中高温制备纠缠态更具前景。
