A binary interface defect is any interface between two (not necessarily
invertible) domain walls. We compute all possible binary interface defects in
Kitaev's Z/pZ model and all possible fusions between them.
Our methods can be applied to any Levin-Wen model. We also give physical
interpretations for each of the defects in the Z/pZ model.
These physical interpretations provide a new graphical calculus which can be
used to compute defect fusion.Comment: 27+10 pages, 2+5 tables, comments welcom