Index theory and bulk-boundary correspondence for inversion-symmetric second-order topological insulators
Published: Sep 11, 2025
Last Updated: Sep 11, 2025
Authors:Shin Hayashi
Abstract
We provide an index-theoretic proof of the bulk-boundary correspondence for two- and three-dimensional second-order topological insulators that preserve inversion symmetry, which are modeled as rectangles and rectangular prism-shaped systems. Our method uses extensions of the symbols of some Toeplitz operators on discrete quarter planes and computations of topological equivariant K-theory groups.