• 文献标题:   Fractional Topological Phases and Broken Time-Reversal Symmetry in Strained Graphene
  • 文献类型:   Article
  • 作  者:   GHAEMI P, CAYSSOL J, SHENG DN, VISHWANATH A
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW LETTERS
  • ISSN:   0031-9007 EI 1079-7114
  • 通讯作者地址:   Univ Illinois
  • 被引频次:   66
  • DOI:   10.1103/PhysRevLett.108.266801
  • 出版年:   2012

▎ 摘  要

We show that strained or deformed honeycomb lattices are promising platforms to realize fractional topological quantum states in the absence of any magnetic field. The strain-induced pseudomagnetic fields are oppositely oriented in the two valleys and can be as large as 60-300 T as reported in recent experiments. For strained graphene at neutrality, a spin-or a valley-polarized state is predicted depending on the value of the on-site Coulomb interaction. At fractional filling, the unscreened Coulomb interaction leads to a valley-polarized fractional quantum Hall liquid which spontaneously breaks time-reversal symmetry. Motivated by artificial graphene systems, we consider tuning the short-range part of interactions and demonstrate that exotic valley symmetric states, including a valley fractional topological insulator and a spin triplet superconductor, can be stabilized by such interaction engineering.