Bandgap modulation of narrow-gap carbon nanotubes in a transverse electric fieldD. Gunlycke, C. J. Lambert, S. W. D. Bailey, D. G. Pettifor, G. A. D. Briggs and J. H. JeffersonEurophys. Lett., 73 5 (2006) 759-764DOI: https://doi.org/10.1209/epl/i2005-10446-x