• 文献标题:   Bosonic field theory of tunable edge magnetism in graphene
  • 文献类型:   Article
  • 作  者:   SCHMIDT MJ
  • 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:   6
  • DOI:   10.1103/PhysRevB.86.075458
  • 出版年:   2012

▎ 摘  要

A bosonic field theory is derived for the tunable edge magnetism at graphene zigzag edges. The derivation starts from an effective fermionic theory for the interacting graphene edge states, derived previously from a two-dimensional Hubbard model for graphene. The essential feature of this effective model, which gives rise to the weak edge magnetism, is the momentum-dependent nonlocal electron-electron interaction. It is shown that this momentum dependencemay be treated by an extension of the bosonization technique and leads to interactions of the bosonic fields. These interactions are reminiscent of a phi(4) field theory. Focusing on the regime close to the quantum phase transition between the ferromagnetic and the paramagnetic Luttinger liquid, a semiclassical interpretation of the interacting bosonic theory is given. Furthermore, it is argued that the universal critical behavior at the quantum phase transition between the paramagnetic and the ferromagnetic Luttinger liquid is governed by a small number of terms in this theory, which are accessible by quantum Monte Carlo methods.