▎ 摘　　要

The band structures of zigzag graphene nanoribbons under uniaxial strain are investigated within the mean-field Hubbard model. In addition to the intrinsic gap modification, the strain can induce two additional gaps in the conduction and valence bands when the compressive strain along the armchair direction or the tensile strain along the zigzag direction is greater than 13%. These band gap variations can be attributed to uniaxial strain which causes the breaking of the lattice symmetry and two different hopping energies. The ratio of the two different hopping energies impacts on the intrinsic and the strain induced gaps. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3593490]