| AVS 55th International Symposium & Exhibition | |
| Graphene Topical Conference | Tuesday Sessions |
| Session GR+EM+NC-TuM |
| Session: | Graphene and Carbon Electronics |
| Presenter: | Y. Liu, The Pennsylvania State University |
| Authors: | Y. Liu, The Pennsylvania State University K.V. Emtsev, University Erlangen-Nurnberg, Germany Th. Seyller, University Erlangen-Nurnberg, Germany R.F. Willis, The Pennsylvania State University |
| Correspondent: | Click to Email |
Using High Resolution Energy Loss Spectroscopy (HREELS), we compare experimental results for the wavevector-dependent behavior of plasmons in a graphene sheet on SiC(0001), with that due to a filled band of surface states on semiconducting silicon. There are significant diffences in behavior between the two systems, and the behavior predicted for a classical two-dimensional sheet of electrons. In particular, the damping increases with wavevector beyond the critical momentum for Landau damping by electron-hole pairs. This unusual behavior is compared with that due to the filling of two dimensional surface states on a metallized silicon surface. The graphene results are a consequence of the unusual collective behavior of Dirac fermions. The effect of adding additional graphene layers is discussed.