• 文献标题:   Dynamical Signatures of Edge-State Magnetism on Graphene Nanoribbons
  • 文献类型:   Article
  • 作  者:   FELDNER H, MENG ZY, LANG TC, ASSAAD FF, WESSEL S, HONECKER A
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW LETTERS
  • ISSN:   0031-9007 EI 1079-7114
  • 通讯作者地址:   CNRS UdS
  • 被引频次:   85
  • DOI:   10.1103/PhysRevLett.106.226401
  • 出版年:   2011

▎ 摘  要

We investigate the edge-state magnetism of graphene nanoribbons using projective quantum Monte Carlo simulations and a self-consistent mean-field approximation of the Hubbard model. The static magnetic correlations are found to be short ranged. Nevertheless, the correlation length increases with the width of the ribbon such that already for ribbons of moderate widths we observe a strong trend towards mean-field-type ferromagnetic correlations at a zigzag edge. These correlations are accompanied by a dominant low-energy peak in the local spectral function and we propose that this can be used to detect edge-state magnetism by scanning tunneling microscopy. The dynamic spin structure factor at the edge of a ribbon exhibits an approximately linearly dispersing collective magnonlike mode at low energies that decays into Stoner modes beyond the energy scale where it merges into the particle-hole continuum.