  Graphene has vast promising applications on the nanoelectronics and
spintronics because of its unique magnetic and electronic properties. Making
use of an ab initio spin-polarized density functional theory, implemented by
the method of Heyd-Scuseria-Ernzerhof 06(HSE06) hybrid functional, the
properties of nitrogen substitutional dopants in semi-metal monolayer graphene
were investigated. We found from our calculation, that introducing nitrogen
doping would possibly break energy degeneracy with respect to spin(spin
symmetry breaking) at some doping concentrations with proper dopant
configurations. The spin symmetry breaking would cause spin-polarized effects,
which induce magnetic response in graphene. This paper systematically analyzed
the dependence of magnetic moments and band gaps in graphene on doping
concentrations of nitrogen atoms, as well as dopant configurations.
