Improving the conductivity of carbon nanotube wires through resonant momentum exchange

Carbon nanotubes (CNTs) have remarkable properties that make them excellent candidates for nano-electronic devices. Retaining these properties in CNT networks scalable for manufacture is a significant challenge. Experiment shows that conductivities of CNT networks are at least an order of magnitude lower than the theoretical maximum based on single CNT performance. In a CNT network, typically no single tube spans the device. As a result, electrons must travel between CNTs in order to contribute to the conductivity. Optimizing the conductivity of CNT networks, therefore, requires a detailed understanding of inter-tube electron transport. To this end, we present theoretical investigations of inter-tube conductivity of CNTs. We find, in agreement with previous studies, that conductivity between CNTs of different chirality is strongly suppressed as a consequence of the requirement for momentum conservation. We show that this problem can be overcome by providing a weak perturbation to the system, resulting in increases in inter-tube conductivity by over one order of magnitude. We will discuss practical realizations of the required perturbation and its experimental relevance for enhancing the conductivity of CNT networks.