Quantum simulation of thermalization dynamics of a nonuniform Dicke model

TL;DR

This work demonstrates quantum simulation of a nonuniform Dicke-like model with 200 ions, revealing how spatial inhomogeneity influences thermalization and multi-spin distributions, advancing understanding of disorder effects in quantum systems.

Contribution

First experimental realization of a nonuniform Dicke-like model in a 2D ion crystal, exploring disorder effects on thermalization and quantum chaos.

Findings

Sensitivity of few-spin observables to spatial inhomogeneity

Measurement of multi-spin distributions affected by nonuniform coupling

Observation of thermalization dynamics via subsystem entropies

Abstract

Previous experimental realizations of Dicke model in atomic or ionic systems are based on global observables assuming uniform spin-boson coupling, while inevitable experimental nonuniformity on the one hand requires site-resolved measurement of spin states, and on the other hand provides potential quantum advantage on the simulation of multi-spin distributions. Here we report the quantum simulation of a nonuniform Dicke-like model in a two-dimensional (2D) crystal of up to 200 ions. We explicitly demonstrate the sensitivity of few-spin observables and multi-spin distributions to the spatial inhomogeneity of the model, and examine the thermalization dynamics of the nonuniform model by measuring the subsystem entropies of selected ion groups. Our work enables the study of Dicke-like models beyond the symmetric subspace, paving the way toward understanding the role of disorder in its thermalization and quantum chaos behavior.