Speaker
Main supervisor (name and email)<br>and his / her institution
Prof S Bhattacharyya (email: Somnath.Bhattacharyya@wits.ac.za)
University of the Witwatersrand.
Level for award<br> (Hons, MSc, <br> PhD)?
PhD
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
Abstract content <br> (Max 300 words)
Direct experimental observation of one dimensional (1D) Plasmon low energy excitations in CNTs using high frequency ac voltages in the Giga Hertz (GHz) range is reported. Evidenced by periodic oscillations in the complex ac impedance of a few aligned single walled (SWNTs) and doubled walled (DWNTs) carbon nanotubes best described by the Luttinger liquid theory we show that this observation is strongly influenced by the number of conduction channels available. Using on-wafer microwave probing up to 65 GHz on coplanar wave guides and an industrially accepted open-short de-embedding technique we further report of a crossover from diffusive transport to ballistic transport at approximately 13 GHz (resulting in a possible 15 ps momentum scattering time) in SWNTs and DWNTs at room temperature. The results are further complimented by the low bias IV characteristics that show quantized conductance in SWNTs and differential conductance characterised by dI/dV α V0.46 consistent with the LL theory. This work provides a direct experimental proof of the LL behaviour which had long been predicted theoretically and indirectly inferred from resonant tunnelling experiments.
