Interaction driven metal-insulator transition in strained graphene

TL;DR

This paper investigates whether electron-electron interactions can induce a metal-insulator transition in graphene, finding that significant strain can turn graphene into an antiferromagnetic Mott insulator.

Contribution

It demonstrates that applying around 15% strain to graphene can drive a transition to an antiferromagnetic Mott insulator, a novel insight into strain-induced electronic phase changes.

Findings

Graphene remains metallic without strain.

Substrate change has minimal effect.

15% strain can induce an antiferromagnetic Mott insulator state.

Abstract

The question of whether electron-electron interactions can drive a metal to insulator transition in graphene under realistic experimental conditions is addressed. Using three representative methods to calculate the effective long-range Coulomb interaction between $\pi$-electrons in graphene and solving for the ground state using quantum Monte Carlo methods, we argue that without strain, graphene remains metallic and changing the substrate from SiO$_2$ to suspended samples hardly makes any difference. In contrast, applying a rather large -- but experimentally realistic -- uniform and isotropic strain of about $15\%$ seems to be a promising route to making graphene an antiferromagnetic Mott insulator.