Observation of energy resolved many-body localization

TL;DR

This paper reports the first experimental observation of an energy-resolved many-body localization transition in a 19-qubit superconducting processor, revealing energy-dependent localization behavior and opening pathways to studying mobility edges.

Contribution

It introduces an experimental method to observe energy-resolved MBL transitions using a programmable quantum processor, providing new insights into the energy dependence of localization phenomena.

Findings

Localization onset varies with energy scale.

Different disorder strengths induce localization at different energies.

Experimental evidence of energy-dependent mobility edges.

Abstract

Many-body localization (MBL) describes a quantum phase where an isolated interacting system subject to sufficient disorder displays non-ergodic behavior, evading thermal equilibrium that occurs under its own dynamics. Previously, the thermalization-MBL transition has been largely characterized with the growth of disorder. Here, we explore a new axis, reporting on an energy resolved MBL transition using a 19-qubit programmable superconducting processor, which enables precise control and flexibility of both disorder strength and initial state preparations. We observe that the onset of localization occurs at different disorder strengths, with distinguishable energy scales, by measuring time-evolved observables and many-body wavefunctions related quantities. Our results open avenues for the experimental exploration of many-body mobility edges in MBL systems, whose existence is widely debated due to system size finiteness, and where exact simulations in classical computers become unfeasible.