2011/04/26 by Alexei Kitaev, Liang Kong · 1 voice · 43 citations
Mathematics · Physics and Astronomy · #Algebraic structures and combinatorial models #Homotopy and Cohomology in Algebraic Topology #Topological Materials and Phenomena #cond-mat.str-el #math.CT #math.QA
paper · pdf · doi:10.1007/s00220-012-1500-5
published as Commun. Math. Phys. 313 (2012) 351-373 · 21 pages, a typo is corrected (thanks for Juven Wang)
arxiv published 2011/04/26 · openalex publication_date 2012/06/06 · arxiv created 2012/09/28 · arxiv updated 2012/10/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/31
We define a class of lattice models for two-dimensional topological phases with boundary such that both the bulk and the boundary excitations are gapped. The bulk part is constructed using a unitary tensor category \calC as in the Levin-Wen model, whereas the boundary is associated with a module category over \calC. We also consider domain walls (or defect lines) between different bulk phases. A domain wall is transparent to bulk excitations if the corresponding unitary tensor categories are Morita equivalent. Defects of higher codimension will also be studied. In summary, we give a dictionary between physical ingredients of lattice models and tensor-categorical notions.