Temperature-dependent diffusive to ballistic transport transition in aligned double walled carbon nanotubes in the high frequency regime

摘要

Low-temperature induced diffusive to ballistic transport in aligned double walled carbon nanotubesud(DWNT) is reported. This is evidenced by a crossover of the imaginary (reactive) component ofudthe alternating current impedance being greater than the real (resistive) component, which happensudin the range of 9 GHz–1.5 GHz at temperatures77K and 4K from which we estimate a longudlifetime of 17 ps and 106 ps in DWNTs, respectively. By simulating the measured scatteringudparameters of a few aligned DWNTs over a wide temperature range, we show that this observationudis strongly influenced by the electrode–DWNT coupling strength