Magnetism and interaction-induced gap opening in graphene with vacancies or hydrogen adatoms: Quantum Monte Carlo study

摘要

We study electronic properties of graphene with finite concentration ofvacancies or other resonant scatterers by a straightforward lattice QuantumMonte Carlo calculations. Taking into account realistic long-range Coulombinteraction we calculate distribution of spin density associated to midgapstates and demonstrate antiferromagnetic ordering. Energy gaps are open due tothe interaction effects, both in the bare graphene spectrum and in thevacancy/impurity bands. In the case of 5 % concentration of resonant scatterersthe latter gap is estimated as 0.7 eV and 1.1 eV for graphene on boron nitrideand freely suspended graphene, respectively.