In the study of quantum spin liquids, the Kitaev model plays a pivotal role due to the fact that its ground state is exactly known as well as the fact that it may be realized in strongly frustrated materials such as α-RuCl3. While topological insulators and superconductors can be investigated by means of topological band theory -- in particular the topological quantum chemistry (TQC) formalism -- the Kitaev model evades such a treatment, as it is not possible to set up a proper single-particle Green's function for it. We instead associate spin operators with ``orbitals'' that give rise to a band structure. It is thereby possible to analyze the corresponding excitation spectrum engendered by these localized excitations by means of TQC. Special attention is given to the low-energy topological edge mode spectrum. Our work sheds light on the question how the TQC formalism may be generalized to strongly correlated and topologically ordered systems like the Kitaev model.
@article{arxiv.2501.11396,
title = {Band representations in Strongly Correlated Settings: The Kitaev Honeycomb Model},
author = {Axel Fünfhaus and Mikel García-Díez and M. G. Vergniory and Thilo Kopp and Stephen M. Winter and Roser Valentí},
journal= {arXiv preprint arXiv:2501.11396},
year = {2025}
}