Symmetric Mass Generation Transition and its Nonequilibrium Critical Dynamics in a Bilayer Honeycomb Lattice Model

TL;DR

This study uses quantum Monte Carlo simulations to investigate the symmetric mass generation transition in a bilayer honeycomb lattice, revealing a new universality class and analyzing its nonequilibrium critical dynamics.

Contribution

First unbiased simulation confirmation of the SMG transition and its critical exponents, establishing a new universality class and exploring nonequilibrium scaling behaviors.

Findings

Confirmed SMG transition at J_c=2.584(8)

Identified a novel universality class with non-mean-field exponents

Observed generalized finite-time scaling in nonequilibrium dynamics

Abstract

Symmetric mass generation (SMG) transitions defy the conventional Landau-Ginzburg-Wilson paradigm by opening a many-body gap without spontaneous symmetry breaking or topological order, attracting intense interest across particle physics and condensed matter physics. Here, we utilize unbiased quantum Monte Carlo simulations to investigate the equilibrium and nonequilibrium critical dynamics of the SMG transition in a bilayer honeycomb lattice model. We unambiguously confirm the existence of an SMG transition at $J_{\text{c}}=2.584(8)$ that separates the Dirac semimetal phase from a symmetry-preserving SMG phase. High-precision extraction of the critical exponents reveals a novel universality class that profoundly departs from mean-field theory. We then extend our study to the nonequilibrium regime, exploring the driven dynamics of the SMG transition. Notably, despite the breakdown of the prerequisites for the celebrated Kibble-Zurek mechanism, the nonequilibrium SMG transition still follows the generalized finite-time scaling. By bridging equilibrium criticality and nonequilibrium dynamics, our work uncovers the universal critical properties of SMG transitions, providing a solid theoretical basis for future experimental studies of SMG physics.