Electronic transport characterization of Sc@C82 single-wall carbon nanotube peapods.

We present electrical transport and Raman measurements on individual single-wall carbon nanotubes filled with the paramagnetic metallofullerene Sc@C₈₂. We find nearly all devices to be metallic p-type conductors, which we tentatively attribute to bandstructure modification of the nanotubes by the encapsulated Sc@C₈₂ molecules. At low temperatures the peapod devices behave as quantum dots and transport is shown to be quantum coherent over distances of at least ∼100 nm. Kondo features are observed at the lowest measurement temperatures of 50 mK. Our results are of fundamental interest because of the long spin coherence times of the unpaired electrons on the Sc@C₈₂ molecules and the possibility this offers for studying one-dimensional spin chains in carbon nanotubes. [ABSTRACT FROM AUTHOR]