Fascinating properties of nanotubes arise when they form intermolecular junctions. In this rapid communication, we demonstrate that such nanotube junctions have atomic scale characteristics and the contact resistance between the tubes depends strongly on atomic structure in the contact region. Our calculations show that the optimal electronic transport between nanotubes occurs when the tubes are in atomic scale registry. The contact resistance can vary several orders of magnitude with atomic scale movements. Phenomena such as the negative differential resistance and nonlinear variation of resistance are found. These properties may lead to new device applications.

• Received 9 February 2001

DOI:https://doi.org/10.1103/PhysRevB.63.161403