Classification of 2D Fermionic Systems with a $\mathbb Z_2$ Flavor Symmetry
High Energy Physics - Theory
2026-04-13 v1 Strongly Correlated Electrons
Mathematical Physics
math.MP
Abstract
We classify superfusion categories describing two-dimensional fermionic systems equipped with the universal fermion-parity symmetry, implemented by a topological defect line (TDL) , and an additional flavor symmetry generated by a TDL. Depending on whether is m-type or q-type, its fusion rules lead to three distinct classes, and solving the super-pentagon equations yields 16 consistent superfusion categories. These are labeled by invariants , which determine the anomaly classes of the symmetries generated by , , and . We also provide explicit realizations using multiple Majorana fermions and comment on implications for fermionic CFTs and gapped phases.
Keywords
Cite
@article{arxiv.2604.09503,
title = {Classification of 2D Fermionic Systems with a $\mathbb Z_2$ Flavor Symmetry},
author = {Chi-Ming Chang and Jin Chen and Fengjun Xu},
journal= {arXiv preprint arXiv:2604.09503},
year = {2026}
}
Comments
17 pages+4 appendices