Hidden-symmetry-protected quantum pseudo-spin Hall effect in optical lattices
Hidden-symmetry-protected quantum pseudo-spin Hall effect in optical lattices
复制标题
光学晶格中隐藏对称性保护的量子赝自旋霍尔效应
DOI：
10.1103/physreva.93.063626
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发表时间：
2016-06
影响因子：
2.9
通讯作者：
Chen Wei
中科院分区：
文献类型：
--
作者：
Hou Jing-Min;Chen Wei
提出了一种在正方形光晶格中实现Z_2拓扑绝缘体的方案。与传统的拓扑绝缘体受时间反演对称性保护不同，这里的光学晶格具有一种新的隐对称性，这种隐对称性决定了目前的Z_2拓扑序。在适当定义赝自旋的情况下，这种拓扑绝缘体的特征在于螺旋边缘态表现出赝自旋-动量锁定，因此它可以被认为是量子赝自旋霍尔绝缘体。导出了Z_2拓扑不变量，并讨论了它的实验检测。
We propose a scheme to realize a new Z_2 topological insulator in a square optical lattice. Different from the conventional topological insulator protected by the time-reversal symmetry, here, the optical lattice possesses a novel hidden symmetry, which is responsible for the present Z_2 topological order. With a properly defined pseudo-spin, such a topological insulator is characterized by the helical edge states which exhibits pseudo-spin-momentum locking, so that it can be considered as a quantum pseudo-spin Hall insulator. The Z_2 topological invariant is derived and its experimental detection is discussed as well.