Graphene, a monatomic carbon sheet, is potentially applicable to a vast area of future technology because of its remarkable electronic and structural properties. One intriguing topic in this field is theoretically expected high spin polarization of the zigzag edge state in graphene nanoribbon. This localized electronic state was experimentally found by our group in 2005. Possible control of the polarization and the bad gap by varying ribbon width and magnetic field is now a hot topic anticipating application to spintronic devices. Recently we have succeeded in fabricating nanoribbons between hexagonal nanopits of monatomic depth with high-quality zigzag edges grown on a graphite surface by hydrogen plasma etching technique. A project theme in this program is to fabricate well aligned arrays of such nanoribbons and nanopits by etching after patterning seed defects on few layers of graphene.

Carbon nanotube (CNT) is a rolled graphene with a nanometer size diameter and a micrometer size length. It is a promising quasi one-dimensional (1D) material for future technology, for example, nanowiring. Depending on rolling chirality, CNT becomes either metallic or semiconducting. Recently we have found that bulk random network of high-purity metallic CNTs, not an isolated CNT, shows surprisingly transport properties expected from the Tomonaga-Luttinger liquid (TLL) theory which describes behaviors of interacting fermions in 1D. A project theme is to extend this finding to a high pressure environment up to 1.5 GPa measuring nonlinear I-V characteristic which should provide us information on roles of junction conductance among individual CNTs.

Electronic properties of the above mentioned graphene and CNT samples will be studied by a variety of experimental techniques including transport, scanning tunneling spectroscopy (STS), magnetic susceptibility, specific heat (if possible) measurements down to 30 mK in magnetic fields up to 13 T.