Tunable Excitons in Bilayer Graphene

ORAL

Abstract

Electrons in monolayer graphene are described by the massless Dirac equation and feature a pseudo spinor. More interestingly, bilayer graphene hosts an electrically tunable bandgap thus allows continuous tuning of the electron mass and the pseudospin. Similar to electron spin, the pseudospin manifests itself as an angular momentum and magnetic moment---both are key in determining the properties of graphene. In this talk, I will discuss our efforts on probing novel tunable exciton physics in gapped bilayer graphene. We observed unusual optical selection rules and extremely large magnetic moments of excitons. These observations are direct signatures of pseudospin effects which can be traced to the Berry curvature microscopically. I will also discuss the connection of these excitons to the valley degree of freedom and the their potential for valleytronic applications.

–

Presenters

  • Long Ju

    Cornell Univ

Authors

  • Long Ju

    Cornell Univ

  • Lei Wang

    Physics, Columbia University, Cornell Univ

  • Ting Cao

    University of California, Berkeley, Physics Department, UC Berkeley and Lawrence Berkeley National Lab, Physics, University of California - Berkeley

  • Takashi Taniguchi

    National Institute for Materials Science, NIMS, National Institute for Material Science, Advanced Materials Laboratory, National Institute for Materials Science, National Institute of Materials Science, Research Center for Functional Materials, National Institute for Materials Science, National Institute for Materials Science (NIMS, Advanced Materials Laboratory, NIMS, National Institute for Materials Science, Advanced Materials Laboratory, National Institue for Materials Science, National Institute of Material Science, National Institute for Matericals Science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, NIMS-Japan

  • Kenji Watanabe

    National Institute for Materials Science, NIMS, National Institute for Material Science, Advanced Materials Laboratory, National Institute for Materials Science, National Institute of Materials Science, Research Center for Functional Materials, National Institute for Materials Science, National Institute for Materials Science (NIMS, Advanced Materials Laboratory, NIMS, National Institute for Materials Science, Advanced Materials Laboratory, National Institue for Materials Science, National Institute of Material Science, National Institute for Matericals Science, Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Advanced materials laboratory, National institute for Materials Science, NIMS-Japan

  • Steven Louie

    Physics, University of California, Berkeley, University of California, Berkeley, Physics, Univ of California - Berkeley, Univ of California - Berkeley, Physics, UC Berkeley, Physics Department, UC Berkeley and Lawrence Berkeley National Lab, Department of Physics, University of California at Berkeley and Materials Sciences Division, Lawrence Berkeley National Laboratory, Department of Physics, University of California, Berkeley, Physics Department, University of California Berkeley and Lawrence Berkeley National Lab, Department of physics, University of California - Berkeley, Lawrence Berkeley National Lab and University of California - Berkeley, Materials Sciences Division, Lawrence Berkeley National Laboratory & Department of Physics, University of California at Berkeley, UC Berkeley and Lawrence Berkeley National Lab, Physics, University of California - Berkeley

  • Farhan Rana

    Cornell Univ

  • Jiwoong Park

    University of Chicago, Chemistry, University of Chicago, Cornell Univ, Department of Chemistry, Institute for Molecular Engineering, and James Franck Institute, University of Chicago

  • James Hone

    Columbia University, Columbia Univ, Mechanical Engineering, Columbia Univ., Mechanical Engineering, Columbia University, Physics, Columbia Univ, Department of Mechanical Engineering, Columbia University

  • Feng Wang

    Physics, Univ of California - Berkeley, University of California, Berkeley, Univ of California - Berkeley, University of California at Berkeley, UC Berkeley and LBNL

  • Paul McEuen

    Laboratory of Atomic and Solid State Physics, Cornell University, Cornell Univ, Physics, Cornell University, Cornell University