Tunable resistance of a carbon nanotube-graphite interface

The transfer of electrons from one material to another is usually described in terms of energy conservation, with no attention being paid to momentum conservation. Here we present results on the junction resistance between a carbon nanotube and a graphite substrate and show that details of momentum conservation also can change the contact resistance. By changing the angula r alignment of the atomic lattices, we found that contact resistance varied by more than an order of magnitude in a controlled and reproducible fashio n, indicating that momentum conservation, in addition to energy conservatio n, can dictate the junction resistance in graphene systems such as carbon n anotube junctions and devices.