Topological transitions of interacting bosons in one-dimensional bi-chromatic optical lattices

TL;DR

This paper investigates topological phase transitions in interacting bosons within one-dimensional bi-chromatic optical lattices, revealing their occurrence due to superlattice strength and interactions, and exploring topological properties of incommensurate phases.

Contribution

It demonstrates that topological phase transitions are a general feature of bosons in 1D bi-chromatic lattices, including effects of interactions and incommensurate phases.

Findings

Topological transitions occur as a function of superlattice strength.

Interactions induce topological phase transitions.

Incommensurate density wave phases have topological character.

Abstract

Ultra-cold atoms in 1D bi-chromatic lattices constitute a surprisingly simple system for the study of topological insulators. We show that topological phase transitions constitute a general feature of bosons in 1D bi-chromatic lattices, and that these transitions may occur both as a function of the superlattice strength and due to inter-site interactions. We discuss in addition the topological character of incommensurate density wave phases in quasi-periodic lattices.