• 文献标题:   Finite-temperature ordering of dilute graphene antiferromagnets
  • 文献类型:   Article
  • 作  者:   FABRITIUS T, LAFLORENCIE N, WESSEL S
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW B
  • ISSN:   1098-0121
  • 通讯作者地址:   Univ Stuttgart
  • 被引频次:   17
  • DOI:   10.1103/PhysRevB.82.035402
  • 出版年:   2010

▎ 摘  要

We employ large-scale quantum Monte Carlo simulations to study the magnetic ordering transition among dilute magnetic moments randomly localized on the graphene honeycomb lattice, induced by long-ranged Ruderman-Kittel-Kasuya-Yoshida interactions at low charge-carrier concentration. In this regime the effective exchange interactions are ferromagnetic within each sublattice, and antiferromagnetic between opposite sub-lattices, with an overall cubic decay of the interaction strength with the separation between the moments. We verify explicitly, that this commensurability leads to antiferromagnetic order among the magnetic moments below a finite transition temperature in this two-dimensional system. Furthermore, the ordering temperature shows a crossover in its power-law scaling with the moments' dilution from a low- to a high-concentration regime.