Observing dynamical localization on a trapped-ion qudit quantum processor

TL;DR

This paper demonstrates the observation of dynamical localization and non-ergodic behavior in a trapped-ion qudit quantum processor, revealing new insights into ergodicity-breaking in higher-dimensional quantum systems.

Contribution

It introduces experimental observation of dynamical localization in a qudit system and links multipartite entanglement measures to ergodic transitions, expanding beyond qubit-based studies.

Findings

Observation of a 3T subharmonic response indicating non-ergodic dynamics

Multipartite entanglement via Quantum Fisher Information reflects ergodic-localized transition

Experimental validation of theoretical models of disorder-free Floquet systems

Abstract

The advancements of quantum processors offer a promising new window to study exotic states of matter. One striking example is the possibility of non-ergodic behaviour in systems with a large number of local degrees of freedom. Here we use a trapped-ion qudit quantum processor to study a disorder-free $S=1$ Floquet model, which becomes prethermal by dynamic localization due to local spin interactions. We theoretically describe and experimentally observe an emergent $3T$ subharmonic response, demonstrating the ability to witness non-ergodic dynamics beyond qubit systems. Our numerical simulations reveal the role played by multipartite entanglement through the Quantum Fisher Information, showing how this quantity successfully reflects the transition between ergodic and localized regimes in a non-equilibrium context. These results pave the way for the study of ergodicity-breaking mechanisms in higher-dimensional quantum systems.