On determining defects identity in carbon nanotubes using charge probes

A metallic carbon nanotube with point-like defects under influence of a local potential due to a point charge probe is theoretically studied. A combination of density functional theory and the Landauer-Büttiker formalism is used to compute the electronic conductance in the zero-voltage limit. From a collection of the results obtained by varying the probe position around different defects the conductance maps are created. The analysis of the conductance maps allows us to formulate conditions under which several point-like defects (the Stone-Wales defect, a simple carbon vacancy, hydrogen-passivated vacancies) can be distinguished and identified in experiments with the help of scanning probe microscopy.This work has been supported by the National Science Centre under the contract DEC-2012/07/B/ST3/03412. We acknowledge that the results of this research have been achieved using the PRACE-3IP project (FP7 RI-312763) resource JUROPA based in Germany at Julich. We also thank the Spanish MICINN for the Grant No. FIS2012-34858 (V.M.G.S. and J.F.) and the Ramón y Cajal Fellowship No. RYC-2010-06053 (V.M.G.S.).Peer Reviewe