| AVS 60th International Symposium and Exhibition | |
| Graphene and Other 2D Materials Focus Topic | Monday Sessions |
| Session GR+EM+NS+SP+TF-MoA |
| Session: | Electronic Properties and Charge Transport in 2D Materials |
| Presenter: | S.G. Louie, University of California, Berkeley and Lawrence Berkeley National Laboratory |
| Correspondent: | Click to Email |
In this talk, we discuss results from some recent theoretical studies on the electronic and optical properties of graphene, monolayer MoS2, and surface states of topological insulators. Owing to their reduced dimensionality and unique electronic structure, these systems present opportunities for study of unusual manifestation of concepts/phenomena that may not be so prominent or have not been seen in bulk materials. Many-body effects and symmetry play a critical role in shaping both qualitatively and quantitatively their spectroscopic properties. Several phenomena will be discussed: 1) Excitonic effects in the optical spectra of graphene, in the form of a strong resonant (hyperbolic) exciton, and how they are altered by carrier doping and quasiparticle lifetime are predicted. 2) The physical origin of the intriguing satellite structures seen in angle-resolved photoemission spectra of graphene is explained. 3) The optical response of monolayer MoS2 is shown to be very rich in features and is dictated by excitonic states with huge binding energies of ~1 eV. 4) For topological insulators, we show that the spin orientation of photoelectrons from the topologically protected surface states in general can be very different from that of the initial states and is controlled by the photon polarization.
This work is supported in part by the National Science Foundation, U.S. Department of Energy, and the Office of Naval Research.