Many-body Euler topology
Strongly Correlated Electrons
2026-01-21 v1
Abstract
Integer and fractional Chern insulators exhibit a nonzero quantized anomalous Hall conductivity due to a spontaneous breaking of time reversal symmetry. To identify nontrivial topology in their time-reversal symmetric many-body spectra, we introduce many-body Euler numbers as a counterpart to many-body Chern numbers. Exemplarily, we perform calculations in a topological Hubbard model that can realize Chern and fractional Chern insulating phases. Furthermore, we lay out a classification scheme to realize different topological phases in interacting systems using symmetry indicators in analogy to topological band theory.
Cite
@article{arxiv.2601.14217,
title = {Many-body Euler topology},
author = {Axel Fünfhaus and Titus Neupert and Thilo Kopp and Roser Valentí},
journal= {arXiv preprint arXiv:2601.14217},
year = {2026}
}