Abstract Submitted to the NANOTUBE'02 Workshop:

The search for potential applications of carbon nanotubes has become a field of growing interest. One of the most spectacular properties of the nanotubes, which might be exploited in a future molecular electronics, is that they can be either metallic or semiconducting depending on their atomic structure. In this respect, connecting on the same molecular structure two or more carbon nanotubes possessing different electronic properties offers the possibility to construct elements of logical devices working at the nanoscopic scale. A few kinds of such nanotube intramolecular junctions have been identified with electron microscopy and local-probe microscopy, and their transport properties have been explored experimentally. In the simplest case, a connection between two nanotubes results from the insertion of a pentagon-heptagon pair in the honeycomb structure that preserves the triple coordination of each C atom. This insertion bends the nanotube to an angle that depends on the distance between the pentagon and heptagon. More complex connections between different carbon nanotubes have been realized, such as T and Y junctions which can be operated as three-terminal nanodevices. In the present contribution, a short review is given of the work devoted so far to the electronic properties of nanotube intramolecular junctions.