Potential drop along carbon nanotube devices with current flow

Electronic transport in carbon nanotube devices is calculated self-consistently and characterized by potential profile, using a non-equilibrium Green function approach. We study the potential drop along structures with two types of scatters: randomly disordered, and nanotube ‘heterojunctions’. While perfectly conducting tubes have a flat potential along the tube axis, all the potential drop taking place at the contacts, highly disordered tubes display a linear potential drop profile, showing diffusive conducting behavior. For a heterojunction in which three metallic tubes are connected by topological defects, the potential drop takes place also at the defect located interfaces. Reference is also made to experimental results and applications.