发表机构
The University of Hong Kong（香港大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对高阶拓扑绝缘体（HOTIs）晶体解理的预测问题，通过解理受阻原子绝缘体发现了依赖解理狄拉克质量的高阶拓扑态，揭示了角零模与悬挂键、质量项的关系及拓扑角的低纠缠熵特性。
AI 中文摘要
基于局域电荷分布的拓扑量子化学对高阶拓扑绝缘体（HOTIs）的晶体解理缺乏预测能力。通过解理受阻原子绝缘体，我们发现一种拓扑相，其特征为e/2分数电荷定域在恰好一半的角上，其余空角则具有间隙电荷的互补空位。这些零能电荷-空位与拓扑角形成空间平衡的几何结构，分别受C2旋转对称性约束。关键的是，我们证明角零模的出现要求特定的悬挂键（作为狄拉克费米子的质量）必须明确暴露于角区域，并微妙地向角区域倾斜；这种严格的方向性通过（2+1）维参数空间内质量项的各向异性演化得到验证。此外，我们发现拓扑角的纠缠熵低于体相，这一行为与实空间能量分布的情况相反。
英文摘要
Topological quantum chemistry based on local charge profiles lacks predictive power for the crystalline cleavage of higher-order topological insulators (HOTIs). By cleaving an obstructed atomic insulator, we discover a topological phase characterized by e/2-fractional charges localized at precisely half of the corners, while the remaining empty corners host complementary vacancies of interstice charge. These zero-energy charge vacancies and topological corners form a spatially balanced geometry, separately localized at four corners. Crucially, we demonstrate that the emergence of corner zero modes dictates that specific dangling bonds acting as the mass of a Dirac fermion-must explicitly expose in, and subtly slope toward, the corner regions. This strict directionality is verified by the anisotropic evolution of the mass term within a (2+1) dimensional parameter space. Moreover, we find that the topological corners acquire lower entanglement entropy compared to the bulk, a behavior opposite to that of the real-space energy distribution which forms an energy-entropy compensation, essentially derived from the topological charge compensation. Our work paves the way for the local chemical environment at topological boundaries, and demonstrates the higher order quantum transport counterparts for high energy Dirac physics.
