We present the results of ab-initio density functional theory based calculations of the stability and reconstruction of zigzag edges in triangular graphene quantum dots. We show that, while the reconstructed pentagon-heptagon zigzag edge structure is more stable in the absence of hydrogen, ideal zigzag edges are energetically favored by hydrogen passivation. Zero-energy band exists in both structures when passivated by hydrogen, however in case of pentagon-heptagon zigzag, this band is found to have stronger dispersion, leading to the loss of net magnetization.
@article{arxiv.1011.0369,
title = {Edge stability, reconstruction, zero-energy states and magnetism in triangular graphene quantum dots with zigzag edges},
author = {Oleksandr Voznyy and Alev Devrim Güçlü and Pawel Potasz and Pawel Hawrylak},
journal= {arXiv preprint arXiv:1011.0369},
year = {2015}
}