Emergent interaction-induced topology in Bose-Hubbard ladders

TL;DR

This paper demonstrates how strong interactions in a bosonic ladder system can induce emergent topological states, leading to localized edge modes and non-trivial topology without complex Hamiltonian design.

Contribution

It reveals that interactions can generate topological localization in bosonic ladders via emergent edge modes, expanding the understanding of topological phenomena in many-body systems.

Findings

Localization of singlon defects due to emergent topological edge modes

Formation of zero-energy edge states in an effective SSH model

Interaction-induced topological behavior without complex Hamiltonian engineering

Abstract

We investigate the quantum many-body dynamics of bosonic atoms hopping in a two-leg ladder with strong on-site contact interactions. We observe that when the atoms are prepared in a staggered pattern with pairs of atoms on every other rung, singlon defects, i.e.~rungs with only one atom, can localize due to an emergent topological model, even though the underlying model in the absence of interactions admits only topologically trivial states. This emergent topological localization results from the formation of a zero-energy edge mode in an effective lattice formed by two adjacent chains with alternating strong and weak hoping links (Su-Schrieffer-Heeger chains) and opposite staggering which interface at the defect position. Our findings open the opportunity to dynamically generate non-trivial topological behaviors without the need for complex Hamiltonian engineering.