Subdiffusive dynamics and critical quantum correlations in a disorder-free localized Kitaev honeycomb model out of equilibrium

TL;DR

This paper demonstrates that a disorder-free Kitaev honeycomb model exhibits nonergodic, subdiffusive dynamics with volume-law entanglement and power-law correlations after a quantum quench, revealing unconventional quantum states beyond equilibrium.

Contribution

It shows that disorder-free localization can induce nonergodic, subdiffusive behavior and novel quantum correlations in a 2D Kitaev model out of equilibrium, expanding understanding of ergodicity breaking mechanisms.

Findings

Nonergodic dynamics observed after a quantum quench.

Subballistic entanglement growth and power-law correlation spreading.

Steady state with volume-law entanglement and power-law decaying correlations.

Abstract

Disorder-free localization has recently emerged as a mechanism for ergodicity breaking in homogeneous lattice gauge theories. In this work we show that this mechanism can lead to unconventional states of quantum matter as the absence of thermalization lifts constraints imposed by equilibrium statistical physics. We study a Kitaev honeycomb model in a skew magnetic field subject to a quantum quench from a fully polarized initial product state and observe nonergodic dynamics as a consequence of disorder-free localization. We find that the system exhibits a subballistic power-law entanglement growth and quantum correlation spreading, which is otherwise typically associated with thermalizing systems. In the asymptotic steady state the Kitaev model develops volume-law entanglement and power-law decaying dimer quantum correlations even at a finite energy density. Our work sheds light onto the potential for disorder-free localized lattice gauge theories to realize quantum states in two dimensions with properties beyond what is possible in an equilibrium context.