Stacking order, interaction and weak surface magnetism in layered graphene sheets

Dong-Hui Xu, Jie Yuan, Zi-Jian Yao, Yi Zhou, Jin-Hua Gao, Fu-Chun Zhang

Published 2012-07-23Version 1

Recent transport experiments have demonstrated that the rhombohedral stacking trilayer graphene is an insulator with an intrinsic gap of 6meV and the Bernal stacking trilayer one is a metal. We propose a Hubbard model with a moderate $U$ for layered graphene sheets, and show that the model well explains the experiments of the stacking dependent energy gap. The on-site Coulomb repulsion drives the metallic phase of the non-interacting system to a weak surface antiferromagnetic insulator for the rhombohedral stacking layers, but does not alter the metallic phase for the Bernal stacking layers.