# Interacting Edge States of Fermionic Symmetry-Protected Topological Phases in Two Dimensions

### Submission summary

 As Contributors: Meng Cheng Arxiv Link: https://arxiv.org/abs/1904.08953v3 Date submitted: 2019-08-23 Submitted by: Cheng, Meng Submitted to: SciPost Physics Domain(s): Theoretical Subject area: Condensed Matter Physics - Theory

### Abstract

Recently, it has been found that there exist symmetry-protected topological phases of fermions, which have no realizations in non-interacting fermionic systems or bosonic models. We study the edge states of such an intrinsically interacting fermionic SPT phase in two spatial dimensions, protected by $\mathbb{Z}_4\times\mathbb{Z}_2^T$ symmetry. We model the edge Hilbert space by replacing the internal $\mathbb{Z}_4$ symmetry with a spatial translation symmetry, and design an exactly solvable Hamiltonian for the edge model. We show that at low-energy the edge can be described by a two-component Luttinger liquid, with nontrivial symmetry transformations that can only be realized in strongly interacting systems. We further demonstrate the symmetry-protected gaplessness under various perturbations, and the bulk-edge correspondence in the theory.

###### Current status:
Editor-in-charge assigned

### Submission & Refereeing History

Submission 1904.08953v3 on 23 August 2019