Gate-Induced Localized States Along Armchair Chain in Graphene 王律堯 ^{1*}, 張哲遠^{2}, 朱仲夏^{2}^{1}物理系, 輔仁大學, 新北市, Taiwan^{2}電子物理系, 交通大學, 新竹市, Taiwan* Presenter:王律堯, email:089948@mail.fju.edu.tw In this presentation, we show that a gate-induced line potential in the armchair-chain direction (along y) on a graphene sheet gives rise to localized states. The generation of these localized states is found once the gate induced potential V0 becomes nonzero. This is demonstrated, for a nonzero ky, by our two findings: (1) that the two valley-associated evanescent states on one side of the line-potential have their pseudospins lying on the same plane, and their relative pseudospin orientation span the 2π angular space when the energy is scanned across the energy gap for the ky, and (2) that the boundary condition for the localized states, formulated into an operator connecting the two evanescent states, has the operator being transformed into a rotation operator by a nonzero V0 , with the rotatio axis normal to the plane of the pseudospins. Our results reveal that the formation of the localized states is topological.
Keywords: armchair graphene , localized state |