Tunable Pseudospin Physics and Excitons in Bilayer Graphene

Monday, October 30, 2017 - 2:30pm

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.  

3 Le Conte Hall
Cornell University