Work

Higher-order topology protected by latent crystalline symmetries

Year: 2025

Type: article

Abstract: We demonstrate that rotation symmetry is not a necessary requirement for the existence of fractional corner charges in C_n C n -symmetric higher-order topological crystalline insulators. Instead, it is sufficient to have a latent rotation symmetry, which may be revealed upon performing an isospectral reduction on the system. We introduce the concept of a filling anomaly for latent crystalline symmetric systems, and propose modified topological invariants. The notion of higher-order topology in two dimensions protected by C_n C n symmetry is thus generalized to a protection by latent symmetry. Our claims are corroborated by concrete examples of models that show non-trivial corner charge in the absence of C_n C n -symmetry. This work extends the classification of topological crystalline insulators to include latent symmetries.

Source: SciPost Physics

DOI: 10.21468/scipostphys.18.2.061

Authors: Lumen Eek, Malte Röntgen, Anouar Moustaj, Cristiane Morais Smith

Institutions: Utrecht University, Centre National de la Recherche Scientifique, Laboratoire d'Acoustique de l'Université du Mans

Language: English

Topic: Topological Materials and Phenomena

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: diamond

Funder: Ministerie van Onderwijs, Cultuur en Wetenschap

Award: G3818296207