Topological symmetry breaking: Domain walls and partial instability of chiral edges

TL;DR

This paper investigates how topological symmetry breaking affects chiral edges in 2D topological systems, leading to domain walls, partial confinement, and edge instabilities, with detailed analysis in fractional quantum Hall models.

Contribution

It provides a detailed analysis of topological symmetry breaking effects on bulk and edge states in chiral fractional quantum Hall systems, highlighting domain walls and edge kinks.

Findings

Domain walls appear due to symmetry breaking.

Edges develop kinks associated with confined particles.

Bulk exhibits partial confinement and instability.

Abstract

In 2D topological systems chiral edges may exhibit a spectral change due to the formation of a Bose condensate and partial confinement in the bulk according to the topological symmetry breaking (TSB) mechanism. We analyze in detail what happens in the bulk as well as on the edge for a set of simple chiral fractional quantum Hall systems. TSB corresponds to the spontaneous breaking of a global discrete symmetry and therefore to the appearance of domain walls in the bulk and kinks on the edge. The walls are locally metastable and break if a confined particle-hole pair is created.