Topological Insulators on the Decorated Honeycomb Lattice

TL;DR

This paper explores topological insulating phases on a decorated honeycomb lattice, revealing their stability, connection to spin liquids, and expanding the understanding of topological states in condensed matter physics.

Contribution

It demonstrates the existence of topological insulators with non-trivial Z_2 invariants on the decorated honeycomb lattice and links them to topologically ordered spin systems.

Findings

Supports topological phases with protected edge modes

Shows stability under symmetry-breaking perturbations

Connects topological insulators to spin liquid models

Abstract

We show that the decorated honeycomb lattice supports a number of topological insulating phases with a non-trivial Z_2 invariant and time-reversal symmetry protected gapless edge modes. We investigate the stability of these phases with respect to various symmetry breaking perturbations and demonstrate the connection to the recently discovered exactly solvable S=1/2 chiral spin liquid model [Phys. Rev. Lett. 99, 247203 (2007)] with non-Abelian and Abelian excitations on the same lattice. Our work highlights the relationship between topological band insulators and topologically ordered spin systems, and points to promising avenues for enlarging the number of known examples of both.