Eur. Phys. J. B 28, 217-222 (2002)
https://doi.org/10.1140/epjb/e2002-00223-9

Very low shot noise in carbon nanotubes

¹ Laboratoire de Physique des Solides (Associé au CNRS) , bâtiment 510, Université Paris-Sud, 91405 Orsay Cedex, France
² Laboratoire de Physique de la Matière Condensée, École Normale Supérieure, 24 rue Lhomond, 75231 Paris Cedex 05, France
³ Institute of Microelectronics Technology and High Purity Materials, Russian Academy of Sciences, Chernogolovka 142432 Moscow Region, Russia

Corresponding author: ^a Philippe.Roche@lpmc.ens.fr

Received: 25 January 2002
Published online: 19 July 2002

Abstract

We have performed noise measurements on suspended ropes of single wall carbon nanotubes (SWNT) between 1 and 300 K for different values of dc current through the ropes. We find that the shot noise is suppressed by more than a factor 100 compared to the full shot noise 2eI. We have also measured an individual SWNT and found a level of noise which is smaller than the minimum expected. Another finding is the very low level of 1/f noise, which is significantly lower than previous observations. We propose two possible interpretations for the strong shot noise reduction: i) Transport within a rope takes place through few nearly ballistic tubes within a rope and possibly involves non integer effective charges with . ii) A substantial fraction of the tubes conduct with a strong reduction of effective charge (by more than a factor 50).