Connection between free-fermion and interacting crystalline symmetry-protected topological phases
Phys. Rev. B 113, 045135 – Published 21 January, 2026
DOI: https://doi.org/10.1103/tzdm-5hzk
Abstract
We present a framework for investigating the effects of interactions on crystalline symmetry-protected topological (SPT) phases. Within this framework, one can establish a direct connection between the equivalence classes of free-fermion systems and their corresponding interacting classes. A central component of this framework is the Atiyah-Hirzebruch spectral sequence, which provides a systematic way to represent crystalline SPT phases as SPT phases with internal symmetries on subspaces. We demonstrate the application of this approach through examples in various dimensions: systems with and reflection symmetry, systems with and rotation symmetry, and systems with and inversion symmetry.