Selective bulk-boundary correspondence in higher-order topological insulators with anticommuting mirror and chiral symmetries
arXiv:2509.22304
The paper studies higher-order topological insulators protected by chiral and anticommuting mirror symmetries, showing that breaking certain mirror symmetries leads to edge‑selective bulk‑boundary correspondence and introducing a new edge‑sensitive topological invariant.
Abstract
We investigate higher-order topological insulators protected by chiral and anticommuting mirror symmetries. Using models in the BDI class, which include the prototypical topological quadrupole insulator, we show that breaking mirror symmetries that anticommute with the chiral operator leads to edge-selective bulk-boundary correspondence, with gap closings and bound states appearing only along a subset of boundaries of the same orientation and codimension. We define a new edge-sensitive topological invariant that distinguishes this mechanism from previous reports of non-topological edge-selection effects.
v3: 10 pages, including 2 appendices, 9 figures; expanded discussion, updated references; code available at https://doi.org/10.5281/zenodo.17203457