• 文献标题:   First-principles calculations of spin-dependent conductance of graphene flakes
  • 文献类型:   Article
  • 作  者:   SAHIN H, SENGER RT
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   2469-9950 EI 2469-9969
  • 通讯作者地址:   Bilkent Univ
  • 被引频次:   82
  • DOI:   10.1103/PhysRevB.78.205423
  • 出版年:   2008

▎ 摘  要

Using ab initio density-functional theory and quantum transport calculations based on nonequilibrium Green's function formalism we study structural, electronic, and transport properties of hydrogen-terminated short graphene nanoribbons (graphene flakes) and their functionalization with vanadium atoms. Rectangular graphene flakes are stable, having geometric and electronic structures quite similar to that of extended graphene nanoribbons. We show that a spin-polarized current can be produced by pure hydrogenated rectangular graphene flakes by exploiting the spatially separated edge states of the flake using asymmetric nonmagnetic contacts. Functionalization of the graphene flake with magnetic adatoms such as vanadium also leads to spin-polarized currents even with symmetric contacts. We observe and discuss sharp discontinuities in the transmission spectra which arise from Fano resonances of localized states in the flake.