Spin-dependent magnetoresistance in multiwall carbon nanotubesX. Hoffer1, Ch. Klinke1, J.-M. Bonard1, L. Gravier1 and J.-E. Wegrowe2
1 IPN, Faculté des Sciences de Base, EPFL - 1015 Lausanne, Switzerland
2 LSI, Ecole Polytechnique, CNRS-UMR 7642 and CEA/DSM/DRECAM 91128 Palaiseau Cedex, France
(Received 5 September 2003; accepted in final form 27 April 2004)
The spin-dependent transport in multiwall carbon nanotubes, obtained by chemical vapour deposition in porous alumina membranes, has been investigated. The zero-bias anomaly is shown to follow the typical power law . In the nanotubes contacted with pads, the magnetoresistance due to the spin-polarised current (SD-MR) is destroyed. In the case of those contacted with pads, however, the SD-MR is observed. These measurements show that both the observation of a typical scaling law of the conductance (for nanotubes up to 1.5 ) and a short spin diffusion length (less than 0.15 with nickel contacts and 0.7 with cobalt contacts) coexist through the nanotube. This observation may be interpreted in terms of a reminiscence of the Luttinger-liquid behaviour with spin-charge separation.
73.63.Fg - Electronic transport in nanoscale materials and structures: Nanotubes.
72.15.Nj - Collective modes (e.g., in one-dimensional conductors).
72.25.Hg - Electrical injection of spin polarized carriers.
© EDP Sciences 2004