Spin-polarized transport in carbon nanotubes

We present transport measurements of ferromagnetically contacted carbon nan otubes. In both single- and multi-walled nanotube devices, a spin valve eff ect is observed due to spin-polarized transport. In one single-walled nanot ube device, the spin-valve effect is suppressed as the influence of Coulomb charging is observed at around 10 K. To help understand the interplay betw een the Coulomb charging and the spin-polarized transport we investigated t he temperature dependence of the carbon nanotube magnetoresistance. (C) 200 0 Academic Press.