Observation of impedance oscillations in single walled carbon nanotube bundles excited by high frequency signals

TL;DR

This paper reports the experimental detection of impedance oscillations in single-walled carbon nanotube bundles at high frequencies, revealing insights into their ballistic transport properties and the influence of tube count.

Contribution

It provides the first experimental observation of impedance oscillations in SWCNTs at microwave frequencies and links these oscillations to ballistic transport characteristics.

Findings

Impedance oscillations observed from 100 MHz to 65 GHz.

A power law dependence of differential conductance on bias voltage.

Estimated long lifetime of 15 ps supporting ballistic transport.

Abstract

We report experimental observation of impedance oscillations in single-walled carbon nanotubes measured from 100 MHz to 65 GHz on coplanar wave guides and a power law dependence of the differential conductance with bias voltage. From the crossover of the real and imaginary parts of the complex impedance observed in the range of 10 GHz, we estimate a long lifetime of 15 ps that can support the claim of ballistic transport. By measuring the scattering parameters at high-frequencies of a few aligned single-walled bundles at low temperatures we show that, this observation is strongly influenced by the number of tubes available.