Observation of impedance oscillations in single-walled carbon nanotube bundles excited by high-frequency signals
Nano-Scale Transport Physics Laboratory, School of Physics, and DST/NRF Centre of Excellence in Strong Materials, University of the Witwatersrand - Johannesburg, South Africa
Received: 26 March 2015
Accepted: 27 July 2015
We report experimental observation of impedance oscillations in single-walled carbon nanotube bundles measured from 10 MHz to 65 GHz on coplanar waveguides 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 at low temperatures we show that this observation is strongly influenced by the number of aligned nanotube bundles present in the devices.
PACS: 68.65.La – Quantum wires (patterned in quantum wells) / 73.21.Hb – Quantum wires / 72.30.+q – High-frequency effects; plasma effects
© EPLA, 2015