[NCTS-Phys seminar] Generalized symmetry in topological phases and quantum error-correcting codes

Title:Generalized symmetry in topological phases and quantum error-correcting codes
Speaker:Dr. Sheng-Jie Huang (Max Planck Institute)
Date:2023/11/29 (Wed.)
Place:4F Lecture Hall, Cosmology Hall, NTU
Topological phases of matter can host a broad class of non-trivial topological defects with varying codimensions. These defects include well-known examples such as point charges and flux loops. The complete algebraic structure of these topological defects defines a higher category, and can be viewed as an emergent higher symmetry. This plays a crucial role both in the classification of phases of matter and the possible fault-tolerant logical operations in topological quantum error correcting codes. In this talk, I will discuss some recent progress in our understanding of the properties of generalized symmetry, topological defects, and their connection to logical operators in (2+1) and (3+1) dimensions. The emphasis will be on invertible defects and higher group symmetry, with discussions centered around various lattice model examples.