Spin injection into carbon nanotubes and a possible application in spin-resolved scanning tunnelling microscopy

We present magnetotransport measurements on multiwall nanotubes contacted b y ferromagnetic electrodes that are 1 mum apart. The observed magnetoresist ance of 2.2% is consistent with a spin-scattering length of at least 380 nm . We further discuss a novel concept for spin-resolved scanning tunnelling microscopy (SR-STM) with a carbon-nanotube tip. The concept relies on a lon g spin-scattering length as well as on spin-dependent scattering at the int erfaces to the ferromagnetic electrodes. The observed magnitude of the magn etoresistance effect and the distance between the electrodes are large enou gh for application in a SR-STM.