CMP Seminars
Electronic states of Dirac electrons in graphene on vicinal SiC substrates and a topological insulator Bi1:5Sb0:5Te1:7Se1:3
Two-dimensional (2D) electrons in graphene and at the surface of three-dimensional (3D) topological insulators have been investigated extensively because of both the fundamental interest and the prospective applications to such as electronics and spintronics. Graphene shows unique electronic properties related to the massless 2D Dirac electron features, and in the helically-spin-polarized surface states of 3D topological insulators, the back-scattering is largely suppressed. In my talk, I will discuss two topics. One is the electronic states of graphene grown on vicinal SiC(0001) substrates. We have studied them by angle-resolved photoemission spectroscopy. The Dirac cone becomes anisotropic in the graphene covering fully the step-and-terrace structure of the substrate, and the nanoribbons on the terraces have an energy gap at the Dirac energy. The other topic is angle-dependent scattering amplitude of the surface electronic states of the topological insulator Bi1:5Sb0:5Te1:7Se1:3, which was studied by quasi-particle interference using STM. The scattering amplitude decreases rapidly when the scattering angle exceeds 100 degree.
Prof. Komori received his Ph.D. in Physics in 1983 from the University of Tokyo. Then he held a postdoctoral fellowship from JSPS and worked at the same university. From the end of 1983 to 1990, he was a research associate in Prof. S. Ikehata’s group at the Department of Physics, the University of Tokyo. During those periods, his major was low-temperature physics, in particular, electronic and magnetic properties of metallic thin films, semiconductors, mesoscopic systems and nano-particles. In 1991, he moved to the present instituete, and started surface science. His research focuses on electronic and magnetic properties of metal and semiconductor surfaces and nanostructures at surfaces using STM and PES. He served on the editorial board of the Journal of Physical Society of Japan (1992-2004), and currently serves as an editor of Surface Science, Elsevier (from April, 2007).