Stable interaction-induced Anderson-like localization embedded in standing waves

TL;DR

This paper demonstrates that interactions in disorder-free superlattices can induce stable Anderson-like localization of bosons, revealing a novel form of self-localization driven solely by particle interactions.

Contribution

It uncovers a new mechanism of interaction-induced self-localization in nonintegrable Bose-Hubbard models, previously overlooked, and proposes an experimental detection scheme.

Findings

Energy level spacings follow Poisson statistics.

Self-localization is solely induced by interactions.

Proposed dynamical scheme for experimental detection.

Abstract

We uncover the interaction-induced \emph{stable self-localization} of bosons in disorder-free superlattices. In these nonthermalized multi-particle states, one of the particles forms a superposition of multiple standing waves, so that it provides a quasirandom potential to localize the other particles. We derive effective Hamiltonians for self-localized states and find their energy level spacings obeying the Poisson statistics for Anderson-like localization. Surprisingly, we find that the correlated self-localization can be solely induced by interaction in the well-studied nonintegrable Bose-Hubbard models, which has been overlooked for a long time. We propose a dynamical scheme to detect self-localization, where long-time quantum walks of a single particle form a superposition of multiple standing waves for trapping the subsequently loaded particles. Our work provides an experimentally feasible way to realize stable Anderson-like localization in translation-invariant disorder-free systems.