Ergodicity breaking meets criticality in a gauge-theory quantum simulator

TL;DR

This paper explores how quantum criticality affects ergodicity and thermalization in lattice gauge theories using Rydberg atom quantum simulators, revealing long-lived coherent oscillations and nonthermal dynamics.

Contribution

It demonstrates the use of Rydberg atom arrays to map the dynamical phase diagram of a lattice gauge theory and uncovers ergodicity breaking due to quantum many-body scars near critical points.

Findings

Identification of a regime of ergodicity breaking with long-lived oscillations

Observation of quantum scars persisting across phase transitions

Analysis of Kibble-Zurek mechanism effects on dynamics

Abstract

Recent advances in quantum simulations have opened access to the real-time dynamics of lattice gauge theories, providing a new setting to explore how quantum criticality influences thermalization and ergodicity far from equilibrium. Using QuEra's programmable Rydberg atom array, we map out the dynamical phase diagram of the spin-1/2 U(1) quantum link model in one spatial dimension by quenching the fermion mass. We reveal a tunable regime of ergodicity breaking due to quantum many-body scars, manifested as long-lived coherent oscillations that persist across a much broader range of parameters than previously observed, including at the equilibrium phase transition point. We further analyze the electron-positron pairs generated during state preparation via the Kibble-Zurek mechanism, which strongly affect the post-quench dynamics. Our results provide new insights into nonthermal dynamics in lattice gauge theories and establish Rydberg atom arrays as a powerful platform for probing the interplay between ergodicity breaking and quantum criticality.