Injection of Polarized Spins and Anti-Localization Caused by Slight Doping of Heavy Impurities into One End of Carbon Nanotubes

Abstract

Electrode atoms are slightly diffused, with only about 5% volume-ratio, into the top end of multi-walled carbon nanotubes (MWNTs), standing in nano-pores of porous Alumina membranes. Diffusion of light-mass materials (carbon and aluminum) leads to weak localization in the Altshuler-Aronov-Spivak (AAS) oscillations, which is qualitatively consistent with previous works on MWNTs. In contrast, we find that diffusion of heavy materials (gold and platinum) changes this weak localization into an anti-localization in…