Speaker
Stefan Hollands
(U of Leipzig)
Description
Anyonic spin chains can be seen as lattice models where topological excitations are built in from the start. I will explain an intimate relationship between such models based unitary modular tensor categories, and the theory of von Neumann sub-factors. In particular, I will introduce a notion of (vertical) defects, which are shown to be governed by an algebraic structure isomorphic to that appearing in 1+1 rational conformal field theories, as developed by Fuchs et. al and by Kawahigashi et. al -- despite the fact that anyonic chains are defined on finite lattices and may lead to gapped Hamiltonians in the scaling
limit. The talk is pedagogical and I emphasize structures that have not appeared previously in the physics literature.
