Valleytronics, which makes use of the two valleys in graphenes, attracts much attention and the valley filter is expected to be central component in valleytronics. We investigate valley-dependent transport properties of the Stone-Wales (SW) and blister defects of graphenes by density functional theory calculations. It is found that the intervalley transition is perfectly suppressed in some structures although the intravalley scattering occurs by the defect states of the SW or blister defects. Using the tight-binding model, the perfect suppression of the intervalley transition in the SW and blister defects is explained by the sublattice symmetry between the A and B sites of the bipartite honeycomb lattice. In addition, introducing the additional carbon atoms to graphenes to form blister defects, the defect states appear near the Fermi level and the energies where the resonant scattering occurs on the $mathrm{K}$ and $mathrm{K}^prime$ channel electrons split. Making use of this splits, the valley-dependent transport property will be achieved by local application of a gate voltage.
Published : "arXiv Mesoscale and Nanoscale Physics".