Spin-orbit coupling effects on transport in carbon nanotubes with adatoms

Rashba term induced by adatoms is introduced and its effect on the transport in finite carbon nanotubes is studied. The spin-orbit coupling leads to spin-flip conductance and splits the conductance peak near the Fermi level due to the break of orbit degeneracy. Moreover, spin-resolved current can be controlled by adjusting the spin-orbit coupling strength. How the spin-orbit coupling affects the tunneling magnetoresistence and the spin-valve effect in the nanotube-based magnetic tunnel junction is also explored. Significant role of electronic spin is confirmed and it may give the prospect for designing new devices by utilizing the SO coupling in carbon nanotubes.