Current saturation in multiwalled carbon nanotubes by large bias

Transport properties of a single multiwalled carbon nanotube (MWNT) have been investigated in vacuum at room temperature. The MWNTs show the large current carrying capacity at large bias due to the ballistic transport. The conductance for a single MWNT around zero bias is ${\text{0.4G}}_0,$ and increases almost linearly with the applied voltage until it reaches its acmes. Being the signature of the ballistic transport for MWNTs, the conductance acmes are observed at the bias of $\text{±5.8\hspace{0.17em}}\mathrm{V}$ equal to ${\text{±2γ}}_0\mathrm{/e,}$ where ${\gamma }_0$ is the π bonding energy for carbon nanotubes. Our calculation shows a similar curve to our experimental results, which further indicates the ballistic transport through the single MWNT.