CSS codes from the Bruhat order of Coxeter groups
Abstract
I introduce a method to generate families of CSS codes with interesting code parameters. The object of study is Coxeter groups, both finite and infinite (reducible or not), and a geometrically motivated partial order of Coxeter group elements named after Bruhat. The Bruhat order is known to provide a link to algebraic topology -- it doubles as a face poset capturing the inclusion relations of the -dimensional cells of a regular CW~complex and that is what makes it interesting for QEC code design. Assisted by the Bruhat face poset interval structure unique to Coxeter groups I show that the corresponding chain complexes can be turned into multitudes of CSS codes. Depending on the approach, I obtain CSS codes (and their families) with controlled stabilizer weights, for example (stabilizer weights~14 and 9) and (weights 16 and 10), and CSS codes with highly irregular stabilizer weight distributions such as . For the latter, I develop a weight-reduction method to deal with rare heavy stabilizers. Finally, I show how to extract four-term (length three) chain complexes that can be interpreted as CSS codes with a metacheck.
Cite
@article{arxiv.2603.16036,
title = {CSS codes from the Bruhat order of Coxeter groups},
author = {Kamil Bradler},
journal= {arXiv preprint arXiv:2603.16036},
year = {2026}
}