Edge effects in Bilayer Graphene Nanoribbons
  We show that the ground state of zigzag bilayer graphene nanoribbons is non-magnetic. It also possesses a finite gap, which has a non-monotonic dependence with the width as a consequence of the competition between bulk and strongly attractive edge interactions. All results were obtained using {ab initio} total energy density functional theory calculations with the inclusion of parametrized van der Waals interactions. 
Matheus P. Lima, A. Fazzio, Ant\^onio J. R. da Silva