We examine an axion string coupled to a Majorana fermion. It is found that there exist a Majorana-Weyl zero mode on the string. Due to the zero mode, the axion strings obey non-abelian statistics.
Cite
@article{arxiv.hep-th/0307005,
title = {Non-Abelian Statistics of Axion Strings},
author = {Masatoshi Sato},
journal= {arXiv preprint arXiv:hep-th/0307005},
year = {2015}
}