Wigner crystallization in a single and bilayer graphene

TL;DR

This paper investigates the potential for Wigner crystallization in single- and bilayer graphene, predicting a tunable Wigner crystal in bilayer graphene at low carrier densities through a real space tight binding model.

Contribution

It extends previous work by predicting Wigner crystallization in bilayer graphene and highlights the role of interlayer coupling in stabilizing the charge-ordered state.

Findings

Wigner crystallization can occur in bilayer graphene at low carrier densities.

Interlayer coupling stabilizes the Wigner crystal in bilayer graphene.

Confirmation of earlier predictions for single-layer graphene.

Abstract

We study the possibility of Wigner crystallization in both single- and and bi-layer graphene using a real space tight binding model. In addition to verifying our earlier prediction for single layer graphene, we predict that the bilayer graphene can undergo a Wigner crystal transition at low enough carrier density thus offering a possibility of tunable and bipolar Wigner crystal. We find that aside from the Coulomb interaction of the carriers of two layers that stabilizes the charge ordered state, so does the inter layer coupling.