论文标题
与自旋轨道偶联
Emergent chiral symmetry in non-bipartite kagome and pyrochlore lattices with spin-orbit coupling
论文作者
论文摘要
能带中的手性对称性似乎是能量水平的完全对称的抗键和键对。仅在具有两部分晶格结构或具有成对基础的Bogoliubov-De-Gennes系统的几类模型中观察到。我们表明，当引入强旋转轨道耦合时，非双色kagome和pyrochlore晶格可以托管手性对称带。在那里，电子通过始终将旋转方向转换向上向下转换，从而向邻居跳动，这使上下旋转底座可以形成虚拟的两分点连接。在三角形单元上定义的量规Wilson Loop操作员用作检测手性对称性的标记，并使用此属性，构建了手性操作员。这使我们能够访问他们的拓扑对称类别，这些类别可以轻松地使用小型扰动变化。
Chiral symmetry in energy bands appears as perfectly symmetric anti-bonding and bonding pairs of energy levels. It has only been observed in a few classes of models with a bipartite lattice structure or Bogoliubov-de-Gennes systems having the pairwise basis. We show that the non-bipartite kagome and pyrochlore lattices can host chiral symmetric bands when the strong spin-orbit coupling is introduced. There, the electrons hop to their neighbors by always converting the spin orientation up-side-down, which allows the up and down spin bases to form fictitious bipartite connections. The gauge invariant Wilson loop operator defined on a triangular unit serves as a marker to detect the presence of chiral symmetry, and using this property, the chiral operator is constructed. This allows us to access their topological symmetry classes that can easily change with small perturbations.
