Sublattice ordering in a dilute ensemble of defects in graphene

TL;DR

This paper demonstrates that in dilute defect ensembles in graphene, long-range electron-mediated interactions can induce spontaneous sublattice ordering, resulting in domain formation with topological insulator properties.

Contribution

It reveals a mechanism for spontaneous sublattice ordering in graphene defects driven by electron-mediated interactions, leading to topologically nontrivial electronic states.

Findings

Sublattice ordering can spontaneously occur in dilute defect ensembles.

Ordered domains exhibit properties of two-dimensional topological insulators.

Long-range interactions are key to the ordering process.

Abstract

Defects in graphene, such as vacancies or adsorbents attaching themselves to carbons, may preferentially take positions on one of its two sublattices, thus breaking the global lattice symmetry. This leads to opening a gap in the electronic spectrum. We show that such a sublattice ordering may spontaneously occur in a dilute ensemble defects, due to the long-range interaction between them mediated by electrons. As a result sublattice-ordered domains may form, with electronic properties characteristic of a two-dimensional topological insulator.