First-principles calculations were used to investigate the interplay between the electronic and magnetic properties of carbon nanotubes containing line defects. Three types of defect were considered: lines of C-O-C epoxy groups, and defects resulting from the substitution of oxygen atoms by CH2 or C2H4 divalent radicals. It was found that the line defects behaved as pairs of coupled graphene edge states, and various electronic and magnetic ground states was predicted as a function of defect type, nanotube diameter and an applied transverse electric field.

Edge States and Magnetism in Carbon Nanotubes with Line Defects. S.S.Alexandre, M.S.C.Mazzoni, H.Chacham: Physical Review Letters, 2008, 100[14], 146801