Quantum transport in carbon nanotubes

We have observed the electronic transport in single- and double-walled Carbon Nano Tubes (CNT) at room temperature, which is found to be ballistic. For single-wall CNT the histograms show peaks at integer values of the conductance quantum G, and there are two channels crossing the Fermi energy. For double-wall CNT we have observed two types of ballistic pathways, whose conductance is 1G and also between 2 and 5 G.From our results we can conclude that the total conductance in multi wall CNT is not simply due to the sum of each sub-band conductance.