Statistical Bubble Localization with Random Interactions

TL;DR

This paper demonstrates that random interactions alone can induce a many-body localized phase in one-dimensional spinless fermions without on-site disorder, revealing a novel form of statistical localization beyond traditional MBL theories.

Contribution

It introduces the concept of statistical localization driven by random interactions, constructs bubble-neck eigenstates with universal area-law entanglement, and confirms the phase's robustness via exact diagonalization.

Findings

Random interactions stabilize many-body localization without on-site disorder.

Constructed eigenstates exhibit universal area-law entanglement entropy.

System transitions to thermalization at weak interactions when hopping dominates.

Abstract

We study one-dimensional spinless fermions with random interactions, but without any on-site disorder. We find that random interactions generically stabilize a many-body localized phase, in spite of the completely extended single-particle degrees of freedom. In the large randomness limit, we construct "bubble-neck" eigenstates having a universal area-law entanglement entropy on average, with the number of volume-law states being exponentially suppressed. We argue that this statistical localization is beyond the phenomenological local-integrals-of-motion description of many-body localization. With exact diagonalization, we confirm the robustness of the many-body localized phase at finite randomness by investigating eigenstate properties such as level statistics, entanglement/participation entropies, and nonergodic quantum dynamics. At weak random interactions, the system develops a thermalization transition when the single-particle hopping becomes dominant.