Observation of Slow Dynamics near the Many-Body Localization Transition in One-Dimensional Quasiperiodic Systems

TLDR

Many‑body localization can arise in interacting systems with strong disorder or quasiperiodic fields, and the transition occurs over a broad range of energy densities, yet prior studies have mainly focused on true‑random disorder. The authors aim to investigate the regime near the many‑body localization transition in quasiperiodic systems and to discuss possible microscopic origins of the observed slow dynamics. They conduct both experimental and numerical studies of quasiperiodic systems close to the transition. They observe slow relaxation of the density imbalance near the transition, similar to true‑random systems, with dynamics that continuously slows as the transition is approached, allowing an estimate of the transition point.

Abstract

In the presence of sufficiently strong disorder or quasiperiodic fields, an interacting many-body system can fail to thermalize and become many-body localized. The associated transition is of particular interest, since it occurs not only in the ground state but over an extended range of energy densities. So far, theoretical studies of the transition have focused mainly on the case of true-random disorder. In this work, we experimentally and numerically investigate the regime close to the many-body localization transition in quasiperiodic systems. We find slow relaxation of the density imbalance close to the transition, strikingly similar to the behavior near the transition in true-random systems. This dynamics is found to continuously slow down upon approaching the transition and allows for an estimate of the transition point. We discuss possible microscopic origins of these slow dynamics.