Local and non-local shot noise in multiwalled carbon nanotubesT. Tsuneta1, P. Virtanen1, F. Wu1, T. Wang2, T. T. Heikkilä1 and P. J. Hakonen1
1 Low Temperature Laboratory, Helsinki University of Technology - FI-02015 Espoo, Finland, EU
2 Chinese Academy of Sciences - Beijing, China
received 20 April 2008; accepted in final form 15 January 2009; published February 2009
published online 13 February 2009
We have investigated shot noise in multiterminal, disordered multiwalled carbon nanotubes (MWNTs) at 4.2 K over the frequency f = 600–850 MHz. Quantitative comparison of our data to semiclassical theory, based on non-equilibrium distribution functions, indicates that a major part of the noise is caused by a non-equilibrium state imposed by the contacts. Our data exhibits non-local shot noise across weakly transmitting contacts while a low-impedance contact eliminates such noise almost fully. Within our model we obtain < 0.1 for the intrinsic Fano factor of our MWNTs. This behavior cannot be explained by the presence of ballistic channels.
73.63.-b - Electronic transport in nanoscale materials and structures.
73.63.Fg - Nanotubes.
05.40.Ca - Noise.
© EPLA 2009