Interference and Interaction in multiwall carbon nanotubes
Abstract
We report equilibrium electric resistance R and tunneling spectroscopy (dI/dV)measurements obtained on single multiwall nanotubes contacted by four metallic Au fingers from above. At low temperature quantum interference phenomena dominate the magnetoresistance. The phasecoherence (l_{φ})and elasticscattering lengths (l_{e})are deduced. Because l_{e} is of order of the circumference of the nanotubes, transport is quasiballistic. This result is supported by a dI/dV spectrum which is in good agreement with the density of states (DOS) due to the onedimensional subbands expected for a perfect singlewall tube. As a function of temperature T the resistance increases on decreasing T and saturates at 110 Kfor all measured nanotubes. R(T) cannot be related to the energydependent DOS of graphene but is mainly caused by interaction and interference effects. On a relatively small voltage scale of the order 10 meV, a pseudogap is observed in dI/dV which agrees with Luttingerliquid theories for nanotubes. Because we have used quantum diffusion based on Fermiliquid as well as Luttingerliquid theory in trying to understand our results, a large fraction of this paper is devoted to a careful discussion of all our results.
 Publication:

Applied Physics A: Materials Science & Processing
 Pub Date:
 1999
 DOI:
 10.1007/s003390051003
 arXiv:
 arXiv:condmat/9905144
 Bibcode:
 1999ApPhA..69..283S
 Keywords:

 PACS: 73.61.Wp;
 72.15.Gd;
 73.20.Fz;
 73.20.At;
 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 14 pages (twocolumn), 8 figures