The experimental creation and annihilation of defects on single-walled carbon nanotubes, using the tip of a scanning tunneling microscope, was reported. The technique used to manipulate the wall structure of a nanotube at the atomic scale consisted of a voltage ramp applied at constant tunneling current between the tip and a nanotube adsorbed on a gold substrate. Topographic images showed an interference pattern at the defect position, while spatially resolved tunneling spectroscopy revealed the presence of localized states in the band gap of the nanotube. Removal of the defect using the same procedure demonstrated the reversibility of the process.

Reversible Defect Engineering of Single-Walled Carbon Nanotubes using Scanning Tunneling Microscopy. M.Berthe, S.Yoshida, Y.Ebine, K.Kanazawa, A.Okada, A.Taninaka, O.Takeuchi, N.Fukui, H.Shinohara, S.Suzuki, K.Sumitomo, Y.Kobayashi, B.Grandidier, D.Stiévenard, H.Shigekawa: Nano Letters, 2007, 7[12], 3623-7