• 文献标题:   Quantum criticality and minimal conductivity in graphene with long-range disorder
  • 文献类型:   Article
  • 作  者:   OSTROVSKY PM, GORNYI IV, MIRLIN AD
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW LETTERS
  • ISSN:   0031-9007
  • 通讯作者地址:   Forschungszentrum Karlsruhe
  • 被引频次:   117
  • DOI:   10.1103/PhysRevLett.98.256801
  • 出版年:   2007

▎ 摘  要

We consider the conductivity sigma of graphene with negligible intervalley scattering at half filling. We derive the effective field theory, which, for the case of a potential disorder, is a symplectic-class sigma model including a topological term with theta=pi. As a consequence, the system is at a quantum critical point with a universal value of the conductivity of the order of e(2)/h. When the effective time-reversal symmetry is broken, the symmetry class becomes unitary, and sigma acquires the value characteristic for the quantum Hall transition.