Low-Energy Physical Properties of Edge States in Nanographite Systems

Abstract

Recent advances in nanotechnology make it possible to fabricate ultra small artificial physical systems like quantum dot, quantum interferometer, quantum wire, etc. in which quantum effects are experimentally observable. Both from the perspective of fundamental physics or potential applications, these artificial systems have generated a lot of excitement as they enabled the realization of a remarkable variety of physical phenomena such as the quantum Hall effect, ballistic transport, Aharonov-Bohm effect, universal conductance uctuation, Kondo effect [1] etc. arising out of the quantum effects. Among such artificial systems, the nanoscopic carbon systems like carbon nanotubes [2–4] and nanographite [5–7] have received enormous attention not only for their intriguing form, but also for their unusual physical properties. In these systems, the geometry of sp2 carbon networks crucially affects the electronic states near Fermi surface [8–10]. Studies with scanning tunneling microscopy and spectroscopy have confirmed the connection between the electronic states of single wall carbon nanotubes (SWCN) and their geometry [11, 12].