Title: Mimicking the edge of 2d topological superconductors and insulators in 1dlattice models
Speaker: Max Metlitski (MIT)
Abstract: It is well known that the edge of a symmetry protected topological phase is anomalous; in particular, it cannot exist without the bulk if the symmetry is implemented in the standard "on-site" manner. In this talk, I'll discuss how an unconventional symmetry realization can be used to mimick the edge of 2d topological insulators and superconductors in local 1d lattice models. In the case of quantum spin-Hall insulators this requires using a symmetry action which is not ``on-site." In the case of topological superconductors (class DIII) the anomaly is more severe and a constrained edge Hilbert space is required. In both cases, we construct 1d Hamiltonians that realize the gapless edge theories: the helical Luttinger liquid and the Ising CFT.