论文标题
轨道移位引起的边界阻塞了拓扑材料，并具有较大的能量差距
Orbital shift-induced boundary obstructed topological materials with a large energy gap
论文作者
论文摘要
我们提出边界是由普通原子位点之间的轨道轨道移动引起的拓扑阶段，但是，高对称力动量（对称指标）的对称特征值无法指示。在开放的边界上，Wannier电荷中心可以转移到与散装的原子不同的原子，从而导致间隙表面状态，高阶铰链状态或角状态。为了证明这种轨道偏移引起的边界阻塞的拓扑绝缘子，我们预测了八个候选物质，所有这些候选物在当前的拓扑数据库中都被忽略了。在相关边界上，金属表面状态，铰链状态或角状态涵盖了较大的体积能量差距（例如，在tlgate $ _2 $中超过1 eV），可以进行实验检测。此外，我们发现这些材料也是具有像表面状态的沙漏的脆弱拓扑绝缘子。
We propose boundary obstructed topological phases caused by Wannier orbital shift between ordinary atomic sites, which, however, cannot be indicated by symmetry eigenvalues at high symmetry momenta (symmetry indicators) in bulk. On the open boundary, Wannier charge centers can shift to different atoms from those in bulk, leading to in-gap surface states, higher-order hinge states or corner states. To demonstrate such orbital-shift-induced boundary obstructed topological insulators, we predict eight material candidates, all of which were overlooked in present topological databases. Metallic surface states, hinge states, or corner states cover the large bulk energy gap (for example, more than 1 eV in TlGaTe$_2$) at related boundary, which are ready for experimental detection. Additionally, we find these materials are also fragile topological insulators with hourglass like surface states.
