XIV. Transport in Nanotubes
Carbon nanotubes (CNTs) are renowed in the scientific community for being both a playground for studying fundamental physical properties and for applications in, to mention a few, electronic, spintronic and gas sensing technologies. However, despite the progresses in growth techniques, CNTs always exhibit structural defects  and their electronic and transport properties will be affected accordingly . In addition, the presence of defects in carbon-based nanostructures has been seen as source of magnetism . Hence, mastering the physics underlying defected CNTs is crucial not only to model realistic systems but also to design new devices.This abstract was created on: 2009/5/29 6:26:25 (EST).
The spin-polarized electron transport properties of carbon nanotubes with vacancies are investigated using first principles and non-equilibrium Green’s function techniques . Carbon atoms with unsaturated bonds are found to behave as quasi-localized magnetic impurities, coupled by long range interactions. The magnetism of carbon nanotubes with reconstructed mono- and tri-vacancies results in spin dependent contuctances and, hence, can be exploited in spintronic devices such as nano-spin valves.
Clarified the properties of CNTs with vacancies, the sensing ability of defected CNTs towards several molecules (NO2, NH3, CO, CO2, H2O) has also been investigated ab initio. Since the adsorption/desorption of molecules induces modulations on the electrical conductivity of the tube, quantum conductances of the CNT-based sensors are predicted, finding that defective nanotubes are sensitive to NO2, NH3, CO, and H2O while molecular selectivity is provided by the nature of the charge transfer.
This work is supported by the project “Nano2Hybrids” (EC-STREP-033311).
 A. Hashimoto et al., Nature 430, 870 (2004); Y. Fan et al., Nat. Mater. 4, 906 (2005); K. Suenaga et al., Nature Nanotech. 2, 358 (2007).
 C. Gomez-Navarro et al., Nature Mater. 4, 534 (2005).
 P. Esquinazi et al., Phys. Rev. Lett. 91, 227201 (2003); S. Talapatra et al., Phys. Rev. Lett. 95, 097201 (2005); Y. Shibayama et al., Phys. Rev. Lett. 84, 1744 (2000).
 Z. Zanolli and J.-C. Charlier, in preparation (2009).
 Z. Zanolli and J.-C. Charlier, submitted (2009).
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