Experimental measurement of angular and overlap dependence of conduction between carbon nanotubes of identical chirality and diameter.

Measurement of the angular and overlap dependence of the conduction between two identical carbon nanotubes (CNTs), with the same diameter and chirality, has only been possible through theoretical calculations; however, our observation of increased resistance adjacent to the junction between two CNTs facilitates such measurements. Since electrical resistance was found to increase with increased diameter ratio, applying 10 V to one of dissimilar diameter CNTs results in cleavage at the junction. Manipulation of the resulting identical CNTs (created by cutting a single CNT) allows for the direct measurement of the angular and parallel overlap conduction. Angular (13 degrees < theta < 63 degrees) dependence shows two minima (22 degrees and 44 degrees) and a maximum at 30 degrees, and conduction between parallel CNTs increases with overall tip separation but shows a sinusoidal relationship with contact length, consistent with the concept of atomic scale registry.