• 文献标题:   Spin exchange interaction with tunable range between graphene quantum dots
  • 文献类型:   Article
  • 作  者:   BRAUN M, STRUCK PR, BURKARD G
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   1098-0121
  • 通讯作者地址:   Rhein Westfal TH Aachen
  • 被引频次:   9
  • DOI:   10.1103/PhysRevB.84.115445
  • 出版年:   2011

▎ 摘  要

We study the spin exchange between two electrons localized in separate quantum dots in graphene. The electronic states in the conduction band are coupled indirectly by tunneling to a common continuum of delocalized states in the valence band. As a model, we use a two-impurity Anderson Hamiltonian which we subsequently transform into an effective spin Hamiltonian by way of a two-stage Schrieffer-Wolff transformation. We then compare our result to that from a Coqblin-Schrieffer approach as well as to fourth-order perturbation theory.