Interaction-induced moir\'e lattices: from mosaic mobility edges to many-body localization

TL;DR

This paper demonstrates that interparticle interactions alone can induce localization and complex mobility edge phenomena in moiré lattice systems without disorder, revealing new many-body phases and transitions.

Contribution

It introduces a model where interactions create effective quasiperiodic potentials, leading to mobility edges and localization, with a novel mapping to higher-dimensional noninteracting models.

Findings

Interaction-driven mosaic potential causes mobility edges.

Transitions among ergodic, critical, and localized phases with increasing interactions.

Mapping to higher-dimensional noninteracting models explains localization phenomena.

Abstract

We study localization driven solely by interparticle interactions in moir\'e lattice systems without intrinsic disorder or externally imposed quasiperiodic potentials. We consider a one-dimensional bilayer with incommensurate lattice constants, described by a spin-dependent Fermi-Hubbard-type model with short-range interlayer interactions, where quasiperiodicity emerges only through interactions. Exact diagonalization shows that quenching hopping in one layer generates an interaction-induced mosaic potential with multiple mobility edges. When both layers are dynamical, increasing interlayer interactions drives transitions among ergodic, critical, and many-body localized regimes, with energy-dependent coexistence in certain parameter ranges. An exact mapping to a noninteracting single-particle model on a higher-dimensional structured graph provides a unified interpretation of these results and suggests an experimentally accessible route to interaction-induced moir\'e physics and localization.