Topological Bose-Mott Insulators in a One-Dimensional Optical Superlattice

TL;DR

This paper investigates topological phases in a one-dimensional Bose-Hubbard model with superlattice potentials, revealing Mott insulator states with nontrivial topological properties characterized by Chern numbers and edge states.

Contribution

It demonstrates that Mott insulator states in a 1D Bose-Hubbard model can be topologically nontrivial, characterized by Chern numbers, and proposes experimental detection methods.

Findings

Mott insulator states exhibit nonzero charge or spin Chern numbers.

Edge states are present in topological Mott insulators.

Density profiles can reveal topological invariants in experiments.

Abstract

We study topological properties of the Bose-Hubbard model with repulsive interactions in a one-dimensional optical superlattice. We find that the Mott insulator states of the single-component (two-component) Bose-Hubbard model under fractional fillings are topological insulators characterized by a nonzero charge (or spin) Chern number with nontrivial edge states. For ultracold atomic experiments, we show that the topological Chern number can be detected through measuring the density profiles of the bosonic atoms in a harmonic trap.