Topological defect lines in two dimensional fermionic CFTs
Chi-Ming Chang, Jin Chen, Fengjun Xu
SciPost Phys. 15, 216 (2023) · published 29 November 2023
- doi: 10.21468/SciPostPhys.15.5.216
- Submissions/Reports
Abstract
We consider topological defect lines (TDLs) in two-dimensional fermionic conformal field theories (CFTs). Besides inheriting all the properties of TDLs in bosonic CFTs, TDLs in fermionic CFTs could host fermionic defect operators at their endpoints and junctions. Furthermore, there is a new type of TDLs, called q-type TDLs, that have no analog in bosonic CFTs. Their distinguishing feature is an extra one-dimensional Majorana fermion living on the worldline of the TDLs. The properties of TDLs in fermionic CFTs are captured in the mathematical language of the super fusion category. We propose a classification of the rank-2 super fusion categories generalizing the $\mathbb{Z}_8$ classification for the anomalies of $\mathbb{Z}_2$ symmetries. We explicitly solve the F-moves for all the nontrivial categories, and derive the corresponding spin selection rules that constrain the spectrum of the defect operators. We find the full set of TDLs in the standard fermionic minimal models and a partial set of TDLs in the two exceptional models, which give CFT realizations to the rank-2 super fusion categories. Finally, we discuss a constraint on the renormalization group flow that preserves a q-type TDL.
Cited by 10
Authors / Affiliations: mappings to Contributors and Organizations
See all Organizations.- 1 Chi-Ming Chang,
- 1 2 Jin Chen,
- 1 3 Fengjun Xu
- 1 Tsinghua University [THU]
- 2 北京应用数学研究院 / Beijing Institute of Mathematical Sciences and Applications [BIMSA]
- 3 厦门大学 / Xiamen University [XMU]
- National Key Research and Development Program of China (through Organization: Ministry of Science and Technology of the People's Republic of China [MOST])
- National Natural Science Foundation of China [NSFC]
- Thousand Young Talents Program of China