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.