Fast scrambling dynamics and many-body localization transition in an all-to-all disordered quantum spin model

TL;DR

This paper investigates how quantum spin systems with all-to-all interactions transition between thermalization and localization, revealing unique scrambling behaviors and potential for experimental realization with superconducting qubits.

Contribution

It introduces a model with homogeneous all-to-all interactions and random potentials, analyzing the transition and scrambling dynamics without semi-classical assumptions.

Findings

Identifies a thermalization-localization transition controlled by disorder strength.

Shows fast operator scrambling occurs in both thermal and localized phases.

Discusses feasible experimental implementation with superconducting qubits.

Abstract

We study the quantum thermalization and information scrambling dynamics of an experimentally realizable quantum spin model with homogeneous XX-type all-to-all interactions and random local potentials. We identify the thermalization-localization transition by changing the disorder strength, under a proper all-to-all interaction strength. The scrambling dynamics in the localization phase shows novel behaviors distinct from that of local models. The operator scrambling grows almost equally fast in both phases. In the thermal phase, we show there exhibits fast scrambling without appealing to the semi-classical limit. We also briefly discuss the experimental realization of the model using superconducting qubit quantum simulators.