Weak topological insulating phases of hard-core-bosons on the honeycomb lattice

Abstract

We study the phases of hard-core-bosons on a two-dimensional periodic honeycomb lattice in the presence of an on-site potential with alternating sign along the different y-layers of the lattice. Using quantum Monte Carlo simulations supported by analytical calculations, we identify a weak topological insulator, characterized by a zero Chern number but non-zero Berry phase, which is manifested at either density 1/4 or 3/4, as determined by the potential pattern. Additionally, a charge-density-wave insulator is observed at 1/2-filling, whereas the phase diagram at intermediate densities is occupied by a superfluid phase. The weak topological insulator is further shown to be robust against any amount of nearest-neighbor repulsion, as well as weak next-nearest-neighbor repulsion. The experimental realization of our model is feasible in an optical lattice setup.

New references added. Introduction modified. A new appendix and two new figures added

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Cited by in corpus (4)

• Learning phases with Quantum Monte Carlo simulation cell
• Supervised learning of an interacting 2D hard-core boson model of a weak topological insulator using correlation functions
• Interaction-driven phase transition in one dimensional mirror-symmetry protected topological insulator
• Chiral Bosonic Topological Insulator on the Honeycomb Lattice with Anisotropic Interactions