• 文献标题:   Novel electronic states in graphene ribbons - Competing spin and charge orders
  • 文献类型:   Article, Proceedings Paper
  • 作  者:   YAMASHIRO A, SHIMOI Y, HARIGAYA K, WAKABAYASHI K
  • 作者关键词:   nanographite, edge state, mobius strip, helical magnetism, domain wall, extended hubbard model
  • 出版物名称:   PHYSICA ELOWDIMENSIONAL SYSTEMS NANOSTRUCTURES
  • ISSN:   1386-9477 EI 1873-1759
  • 通讯作者地址:   Natl Inst Adv Ind Sci Technol
  • 被引频次:   21
  • DOI:   10.1016/j.physe.2003.12.100
  • 出版年:   2004

▎ 摘  要

In a nanographene ring with zigzag edges, the spin-polarized state and the charge-polarized state are stabilized by the on-site and the nearest-neighbor Coulomb repulsions, U and V, respectively, within the extended Hubbard model under the mean-field approximation. In a Mobius strip of the nanographene with a zigzag edge, U stabilizes two magnetic states, the domain wall state and the helical state. Both states have ferrimagnetic spins localized along the zigzag edge while the former connects the opposite ferrimagnetic orders resulting in a magnetic frustration forced by the topology and the latter rotates the ferrimagnetic spins uniformly to circumvent the frustration. The helical state is lower in energy than the domain wall state. On the other hand, V stabilizes another domain wall state connecting the opposite charge orders. (C) 2003 Elsevier B.V. All rights reserved.