Abstract:

The massless Dirac particle moving at the speed of light has been a  fascinating subject in relativistic quantum physics. Graphene, an isolated
single atomic layer of graphite, now provides us an opportunity to investigate such exotic effect in low-energy condensed matter systems. The
unique electronic band structure of graphene lattice provides a linear dispersion relation where the Fermi velocity replaces the role of the speed
of light in usual Dirac Fermion spectrum. In this presentation I will discuss experimental consequence of charged Dirac Fermion spectrum in two
representative low dimensional graphitic carbon systems: 1-dimensional carbon nanotubes and 2-dimensional graphene. Combined with semiconductor
device fabrication techniques and the development of new methods of  nanoscaled material synthesis/manipulation enables us to investigate
mesoscopic transport phenomena in these materials. The exotic quantum transport behavior discovered in these materials, such as room temperature
ballistic transport and unusual half-integer quantum Hall effect. In addition, the promise of these materials for novel electronic device
applications will be discussed.