Gated Spin Transport through an Individual Single Wall Carbon Nanotube
  Hysteretic switching in the magnetoresistance of short-channel, ferromagnetically contacted individual single wall carbon nanotubes is observed, providing strong evidence for nanotube spin transport. By varying the voltage on a capacitively coupled gate, the magnetoresistance can be reproducibly modified between +10% and -15%. The results are explained in terms of wave vector matching of the spin polarized electron states at the ferromagnetic / nanotube interfaces. 
Bhaskar Nagabhirava, Tanesh Bansal, Gamini Sumanasekera, Lei Liu, and   Bruce W. Alphenaar