锯齿型石墨烯纳米带边界态

Study of Edge States in Zigzag Graphene Nanoribbon

基于Kane-Mele紧束缚模型,在包含自旋轨道耦合作用和塞曼作用项后,我们又引入更为合理的自洽在位库仑相互作用,分析研究各相互作用项对边界带的能带结构和电子分布特征的影响.研究结果表明,自旋轨道耦合作用导致自旋简并劈裂出现非常小的能隙,自洽在位库仑相互作用可使能隙增加,边界带范围增加,而塞曼效应却能保护边界带原有的拓扑属性,使边界带穿过能隙,同时也保护边界态在局域边界的自旋极化特征;4个边界能带由左右两组边界子能带系构成,各边界子能带系在费米能处形成左右能隙和费米波矢,其自旋量子霍尔系统构型属于B型.

Based on the Kane-Mele tight binding model,including spin orbit couplings(SOCs)and Zeeman effect,we introduce a more reasonable self-consistent on-site Coulomb interactions(O-CIs)to analyze and study the band structure and the characteristics of electronic distribution for edge bands.The research results show that the SOCs can lead to spin-flitting and let a small energy gap appear,the O-CIs can increase the energy gap and enlarge the region of edge states,and the Zeeman effect can protect the original topological properties of edge bands passing through the energy gap,it also protects the spin polarization characteristics at the edge sites.The four edge bands are classified into the left and the right sets of edge sub-band,corresponding to the left and the right energy gap and Fermi wave vector.Its spin quantum Hall system belongs to the type B.