Topological bosonic states on ribbons of honeycomb lattice

TL;DR

This paper investigates topological phases of hardcore bosons on honeycomb lattice ribbons, revealing a topological insulator state characterized by edge states and nontrivial Berry phase, with potential realization in cold atom experiments.

Contribution

It demonstrates the existence of a topological bosonic insulator state on honeycomb ribbons and provides an intuitive fermionic mapping, advancing understanding of bosonic topological matter.

Findings

Identified a topological bosonic insulator at half filling.

Showed robustness of edge states against weak interactions.

Mapped the bosonic topological state to a fermionic model.

Abstract

The topological properties of hardcore bosons on ribbons of honeycomb lattice are studied using quantum Monte Carlo simulations. We map out a rich phase diagram with the superfluid and insulator phases at various fillings. Particularly, it is revealed that the insulator state at half filling is a topological bosonic state, which is characterized by a nontrivial Berry phase and a pair of edge states. We provide intuitive picture to understand this topological bosonic insulator state by showing that it can be adiabatically mapped to a topological fermionic model. It is also shown that the topological edge states are robust against weak interactions beyond the hardcore repulsion. Our results can be simulated by using bosonic cold atoms trapped in designed optical lattices.