Crossed nanotube junctions

Junctions consisting of two crossed single-walled carbon nanotubes were fab ricated with electrical contacts at each end of each nanotube. The individu al nanotubes were identified as metallic (M) or semiconducting (S), based o n their two-terminal conductances; MM, MS, and SS four-terminal devices wer e studied. The MM and SS junctions had high conductances, on the order of 0 .1 e(2)/h (where e is the electron charge and h is Planck's constant). For an MS junction, the semiconducting nanotube was depleted at the junction by the metallic nanotube, forming a rectifying Schottky barrier. We used two- and three-terminal experiments to fully characterize this junction.