Critical quench dynamics of Wegner's $\mathbb{Z}_2$ gauge model: a geometric perspective

TL;DR

This study explores the non-equilibrium critical dynamics of Wegner's $ ext{Z}_2$ gauge model using geometric objects, revealing a robust dynamical exponent and scaling behavior during quenches from different initial states.

Contribution

It provides a detailed geometric analysis of the critical quench dynamics in Wegner's $ ext{Z}_2$ gauge model, highlighting a universal dynamical exponent and scaling laws.

Findings

Critical non-equilibrium relaxation governed by $z_{p} \, \simeq \, 2.6$

Dynamical scaling observed with lengthscale $\, \xi_{p}(t) \, \sim \, t^{1/z_{p}}$

Robustness of $z_{p}$ across initial conditions and geometrical objects

Abstract

Wegner's $\mathbb{Z}_2$ gauge model is the earliest formulation of pure lattice gauge theory and predicts the topological nature of the confinement-deconfinement transition. In three dimensions ($D=3$), the equilibrium critical behavior of the model is understood in terms of geometrically defined objects, namely loop excitations and Fortuin-Kasteleyn (FK) clusters. This work investigates the critical quench dynamics of this model from a geometric perspective, following quenches from both a high-temperature percolation phase and the zero-temperature ground state. Using time-dependent finite-size scaling analysis, we find that the critical non-equilibrium relaxation of the percolation order parameter is governed by a dynamical exponent $z_{\rm p} \simeq 2.6$, consistent with that associated with the energy density, $z_{\rm c}$. Importantly, the value of $z_{\rm p}$ is robust with respect to the initial quench condition and the choice of geometrical objects. Furthermore, we provide a detailed characterization of the kinetics of different geometrical objects during the evolution from the percolation phase. Notably, we observe that the quench dynamics obeys dynamic scaling in terms of a growing lengthscale, $\xi_{\rm p}(t) \sim t^{1/z_{\rm p}}$, despite the absence of a local order parameter.