Fate of Quantum Many-Body Scars in the Presence of Disorder

Abstract

Experiments performed on strongly interacting Rydberg atoms have revealed surprising persistent oscillations of local observables. These oscillations have been attributed to a special set of nonergodic states, referred to as quantum many-body scars. Although these states have enriched our understanding of thermalization in quantum systems, their interplay with disorder in realistic quantum simulators has remained unclear. We address this question by studying numerically and analytically the magnetization and spatiotemporal correlators of a scar model of disordered and interacting qubits that can be realized in present-day simulators. While the oscillation amplitudes of these observables decay with time as the disorder strength is increased, their oscillation frequency remains remarkably constant. This stability stems from resonances of the disordered spectrum in the overlap with the clean scar eigenstates that are approximately centered at the same scar energies of the clean system. We also find that multiple additional sets of scar resonances become accessible due to the presence of disorder and further enhance the oscillation amplitudes. Our results show the robustness of nonergodic dynamics in scar systems, and opens the door to understanding their behavior in near-term quantum devices and potentially using them as a resource in quantum-sensing protocols to calibrate quantum hardware.