Quantum conductance steps in solutions of multiwalled carbon nanotubes

Abstract

We have prepared solutions of multiwalled carbon nanotubes in Aroclor 1254, a mixture of polychlorinated biphenyls. The solutions are stable at room temperature. Transport measurements were performed using a scanning–tunneling probe on a sample prepared by spin–coating of the solution on gold substrates. Conductance steps were clearly seen. An histogram of a high number of traces shows maximum peaks at integer values of the conductance quantum G0 = 2e2/h, demonstrating ballistic transport at room temperature along the carbon nanotube over distances longer than 1.4μm.