# Symmetric Fermion Mass Generation as Deconfined Quantum Criticality

## TL;DR

This paper proposes a novel deconfined quantum criticality framework to describe symmetric mass generation in 2+1D Dirac fermions, involving emergent gauge fields and critical Higgs bosons, supported by parton constructions and numerical predictions.

## Contribution

It introduces a new theory for the SMG transition that departs from Landau paradigms, using emergent non-Abelian gauge fields coupled to fermions and Higgs bosons.

## Key findings

- Predicts a zero to pole transition in fermion Green's function at criticality
- Provides a parton construction supporting the deconfined criticality scenario
- Aligns with numerical observations of SMG in various models

## Abstract

Massless 2+1D Dirac fermions arise in a variety of systems from graphene to the surfaces of topological insulators, where generating a mass is typically associated with breaking a symmetry. However, with strong interactions, a symmetric gapped phase can arise for multiples of eight Dirac fermions. A continuous quantum phase transition from the massless Dirac phase to this massive phase, which we term Symmetric Mass Generation (SMG), is necessarily beyond the Landau paradigm and is hard to describe even at the conceptual level. Nevertheless, such transition has been consistently observed in several numerical studies recently. Here, we propose a theory for the SMG transition which is reminiscent of deconfined criticality and involves emergent non-Abelian gauge fields coupled both to Dirac fermions and to critical Higgs bosons. We motivate the theory using an explicit parton construction and discuss predictions for numerics. Additionally, we show that the fermion Green's function is expected to undergo a zero to pole transition across the critical point.