▎ 摘 要
Within determinant quantum Monte Carlo simulation, it is found that the armchair graphene nanoribbons show carrier mediated magnetic correlation. The antiferromagnetic correlation dominates around half filling, while the ferromagnetic correlation dominates as electron filling is lower than 0.8. As the ferromagnetic properties sensitively depend on electron fillings, it may be manipulated by electric gates. Moreover, the ferromagnetic correlation is strengthened markedly as the next-nearest-neighbor hopping energy increases. The predicted manipulation of ferromagnetic correlation may be realized in armchair graphene nanoribbons and ultracold atoms system. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4757962]