Gap opening in graphene by simple periodic inhomogeneous strain
Abstract
Using ab-initio methods, we show that the uniform deformation either leaves graphene (semi)metallic or opens up a small gap yet only beyond the mechanical breaking point of the graphene, contrary to claims in the literature based on tight-binding (TB) calculations. It is possible, however, to open up a global gap by a sine-like one-dimensional inhomogeneous deformation applied along any direction but the armchair one, with the largest gap for the corrugation along the zigzag direction (~0.5 eV) without any electrostatic gating. The gap opening has a threshold character with very sharp rise when the ratio of the amplitude A and the period of the sine wave deformation lambda exceeds (A/lambda)_c ~0.1 and the inversion symmetry is preserved, while it is threshold-less when the symmetry is broken, in contrast with TB-derived pseudo-magnetic field models.
Keywords
Cite
@article{arxiv.1104.0314,
title = {Gap opening in graphene by simple periodic inhomogeneous strain},
author = {I. I. Naumov and A. M. Bratkovsky},
journal= {arXiv preprint arXiv:1104.0314},
year = {2015}
}
Comments
6 pages, 6 figures; (v2) added figures illustrating opening gap in Graphene mesh on BN, expanded analysis illustrating absence of pseudo-magnetic fields in deformed Graphene