Fragile dislocation modes in obstructed atomic topological phases

Autor: Malavé, Gabriel, Schifferli, Jorge, Soto-Garrido, Rodrigo, Orellana, Pedro A., Juričić, Vladimir
Rok vydání: 2023
Předmět:
Zdroj: Phys. Rev. B 109, L201407, 2024
Druh dokumentu: Working Paper
DOI: 10.1103/PhysRevB.109.L201407
Popis: We here introduce the concept of fragile topological dislocation modes, which are localized only in a fraction of a topological phase, while otherwise leak into the bulk continuum. We show that such dislocation modes are hosted in an obstructed atomic topological phase in the two-dimensional Su-Schrieffer-Heeger model, but only in a finite region with an indirect gap at high energy. These dislocation modes are realized as chiral pairs at finite energies with protection stemming from a combination of the chiral (unitary particle-hole) and the point group (C$_{4v}$) symmetries, but only when the indirect gap is open. In this regime, we corroborate the stability of the defect modes by following their localization and also by explicitly adding a weak chemical potential disorder. Our findings, therefore, should be consequential for the experimental observation of such modes in designer topological crystals and classical metamaterials.
Comment: Accepted for publication as a letter in PRB: 6 pages, 5 figures (Supplementary Information as Ancillary file)
Databáze: arXiv