Strong to weak interacting-topological phase transition of bosons on a lattice

TL;DR

This paper investigates a phase transition in hard-core bosons on a honeycomb lattice, revealing a change from strong to weak topological order driven by anisotropic hopping and interactions, characterized by entanglement entropy measures.

Contribution

It introduces a detailed quantum Monte Carlo study of topological phase transitions in bosonic lattice systems with anisotropic parameters, highlighting new entanglement-based signatures.

Findings

Identification of a transition from strong to weak topological order

Characterization of phases by topological and bipartite entanglement entropy

Observation of abrupt changes in order parameters at the transition

Abstract

We study hard-core bosons on the honeycomb lattice subjected to anisotropic nearest-neighbor hopping along with anisotropic nearest-neighbor repulsion, using a quantum Monte Carlo technique. At half-filling, we find a transition from strong interacting-topological order to weak interacting-topological order as function of the hopping anisotropy. The strong topological phase is characterized by a finite topological entanglement entropy, while the weak topological order is identified with a non-trivial value of the bipartite entanglement entropy. Some of the order parameters and their derivatives demonstrate abrupt changes when varying the parameters controlling the lattice anistropies, thus revealing the nature of this interacting-topological phase transition.