  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.
