• 文献标题:   Competition between excitonic gap generation and disorder scattering in graphene
  • 文献类型:   Article
  • 作  者:   LIU GZ, WANG JR
  • 作者关键词:  
  • 出版物名称:   NEW JOURNAL OF PHYSICS
  • ISSN:   1367-2630
  • 通讯作者地址:   Univ Sci Technol China
  • 被引频次:   12
  • DOI:   10.1088/1367-2630/13/3/033022
  • 出版年:   2011

▎ 摘  要

We study the disorder effect on the excitonic gap generation caused by strong Coulomb interaction in graphene. By solving the self-consistently coupled equations of dynamical fermion gap m and disorder scattering rate Gamma, we have found a critical line on the plane of interaction strength lambda and disorder strength g. The phase diagram is divided into two regions: in the region with large lambda and small g, m not equal 0 and Gamma = 0; in the other region, m = 0 and Gamma not equal 0 for nonzero g. In particular, there is no coexistence of finite fermion gap and finite scattering rate. These results imply a strong competition between excitonic gap generation and disorder scattering. This conclusion does not change when an additional contact four-fermion interaction is included. For sufficiently large lambda, the growing disorder may drive a quantum phase transition from an excitonic insulator to a metal.