Critical theories connecting gapped phases with $\mathbb{Z}_2\times\mathbb{Z}_2$ symmetry from the duality web

TL;DR

This paper constructs and analyzes conformal field theories that describe phase transitions between symmetry-broken and topological phases in 1+1D systems with  symmetry, using duality webs and gauging operations.

Contribution

It provides a full field theory formulation of the Kennedy Tasaki transformation and explores the duality web connecting multiple critical and gapped phases.

Findings

Identified 9 critical theories per web connecting 4 gapped phases.

Mapped bosonic and fermionic webs via bosonization.

Described multi-critical and partially gapped topological phases.

Abstract

We use the ideas behind the duality web to construct numerous conformal field theories mediating the phase transitions between various symmetry broken and topological phases. In particular we obtain the full field theory version of the Kennedy Tasaki transformation, mapping a gapless theory mediating a topological phase transition of symmetry protected topological orders to a standard symmetry breaking one in a 1+1 dimensional $\mathbb{Z}_2 \times \mathbb{Z}_2$ gauge theory. When we consider all possible discrete gauging operations, we obtain bosonic and fermionic webs with 9 critical theories per web, each connecting 4 separate gapped phases, some of them topological. Bosonization maps the two webs into each other. In addition to discussing the multi-critical theory connecting the four gapped phases in each phase diagram, we discuss the partially gapped theories connecting two of those four. Some of these are gapless symmetry protected topological phases.